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Main Ideas

• Magnetic force is a force (like gravity) that can operate without physically touching an object.
• All magnets are made of metal,but not all metals are magnetic.
• Students will explore the north and south poles of magnets and how they interact.

Background

Magnets create an invisible force field that can make other magnets or magnetic objects move without touching them. We use magnets everyday, from attaching pictures to our fridges to using compasses to navigate. In fact, the Earth itself is a magnet!

A magnet has two ends called poles, one of which is called a north pole or north-seeking pole, while the other is called a south pole or south-seeking pole. The north pole of one magnet attracts the south pole of a second magnet, while the north pole of one magnet repels the other magnet's north pole. So we have the common saying: like poles repel, unlike poles attract. A magnet creates an invisible area of magnetism all around it called a magnetic field. The north pole of a magnet (like the magnet in a compass) points roughly toward Earth's south pole and vice-versa. That's because Earth itself contains magnetic materials and behaves like a gigantic magnet. If you cut a bar magnet in half, you get two brand new, smaller magnets, each with its own north and south pole. If you run a magnet a few times over an unmagnetized piece of a magnetic material (such as an iron nail), you can convert it into a magnet as well. This is called magnetization.

Fun Facts:

• The Earth's magnetic field protects us from harmful solar charged particles (solar wind)
• The number of electrons around the atoms in a metal determines whether the metal is magnetic or not

Introduction

1. Tell them we’ll be using science to figure out what is in our mystery box.
   1. You can have the discussion on magnets as part of the wrap-up, so we can keep our mystery box a mystery.
2. In order to figure out what’s in our box we’re going to try to characterize it without looking at it. Is it hard or soft? Heavy or light? We’re going to see if other objects can interact with it. You can give examples like how the wind moves the leaves in a tree or how velcro sticks together.
3. After they’ve determined what is in the mystery box, introduce them to today’s lesson and magnetism. What do magnets do? What can magnets attach to? Lead them to the ideas of attraction and repulsion.

Activity Directions

PART 1: The mystery box

1. Introduce the “mystery” boxes to the students. Each pair will be given a box that is taped shut, and a bag of objects they can use to explore the box. Explain that their job is to figure out what is inside the box without opening it. They can use the objects to do this, but they cannot damage the box in any way (no poking, cutting, etc.)
2. After a few minutes of exploring, students will start to figure out that there is a magnet in the box (Don’t tell them ahead of time!).
   1. Ask if they can use the objects to figure out where the magnet is located in the box.
3. Ask for the students’ attention (I would have them put the objects back in the bag first). Ask them, How can we keep track of which objects help you find the magnet and which ones do not? Someone will probably suggest putting the objects in piles. Have the students sort the objects into two piles: those that “stick” to the box and those that do not
4. After students have done this, have them help you make a list on the board of the two groups. Those objects that “stick” to the box are magnetic (label them as such). Ask the students what they notice about all the objects that stick to the box. Students will probably comment that they are all made of metal. Ask them, If objects have to be metal to stick to the magnet, why doesn’t the aluminum foil, the coin, or the gold fastener stick to the magnet? Guide students to the idea that only certain kinds of metals are magnetic.

PART 2: Magnetic force and further magnet explorations

1. Collect the boxes and objects from the students so that you can move on to the 2nd part of the activity. Explain that magnetic force is a special kind of force because it works without touching. Normally you need a push or pull to get an object to move, but magnetic force can make an object move without physical contact!
   1. Ask if the students remember the other force that makes objects move without touching. Gravity!
2. Tell the students that they will get two magnets per pair, and ask what they think the magnets will do. Kids often only think of magnets as attracting, but forget about the repelling part.
3. Give each pair of students two magnets and a pencil to thread them onto (if they are using the square magnets they may need the wooden dowels). Challenge them to make the magnets move without touching them to each other. The north and south poles will be labeled with tape.
4. Once the kids have seen this with their two magnets, have them trade just one of their magnets with someone who has a differently shaped magnet. Do they see the same pattern with two magnets of different shapes? This can lead into a discussion of how ALL magnets have a north and south pole.

PART 3: Can we see magnetic field lines?

1. Show the students a picture of the earth with artistically added magnetic field lines. Tell them that these lines are invisible. Ask the students if there is any way we might be able to see these lines.
2. Place a bar magnet on a piece of white paper and gently shower the area with iron filings. The iron filings will align with the north and south poles of the magnet. Do this in small groups with a volunteer at each station. Make sure to collect all of the iron filings after the demonstration.

PART 4 (if there is enough time): Which magnet is the strongest?

1. If there is time, you can challenge the students to figure out which magnet (square or circle) is the strongest. To do this they can do the “paper-clip test”. Have them figure out which magnet can hold the longest paper-clip chain. For this chain you will NOT actually loop the paperclips together. Instead you are just relying on the magnetic force to make the chain.

Wrap-up

1. Ask a few of the students to share what they learned and what they liked best about the lesson.
2. Emphasize the main ideas, and ask the students to share their results from each part of the experiment.
3. Check to see if there are any lingering questions.
4. Thank the teacher and class on your way out. Remember to get the feedback slip back from the teacher!

Packing List

• Lesson plans
• Baggie of sharpies, tape, dry erase markers, pens
• Stack of Observation Sheets
• “Mystery box” containing a magnet
• Pencils
• Pennies
• Aluminum foil
• Paper clips
• Washers
• Erasers
• Nails and/or screws
• Roundhead fasteners
• Magnets
• Iron filings
• compass

Main Ideas

• Scientists plan and perform experiments to test their hypotheses.
• Generally, we change only one variable at a time in an experiment in order to determine cause and effect.

Background

The candy coating on a Skittle is made up of food coloring and sugar, both of which are water-soluble. This is why the color comes off the skittle when it is placed in water. The same case goes for the M&M, though the chocolate on the inside of the M&M will dissolve more slowly than the inside of the Skittle.

Fun facts:

• Skittles were invented in 1974 in Britain
• When you taste sourness in candy, you are tasting citric acid, the same chemical that makes lemons sour
• Sugar (glucose) is made of the elements carbon, oxygen, and hydrogen arranged in a ring.��

Introduction

1. Ask the students what they learned about the previous week’s activity and introduce today’s activity��(Ex. What do you remember from last week’s experiment?)
2. Tell them that this week we are going to design another experiment! Ask them if they’ve ever put baking soda into vinegar?
   
   0. Do a demonstration of baking soda into vinegar in a small container. There should be lots of fizzing and you can explain that CO2 is given off in this chemical acid-base reaction.
3. Ask them what they think would happen if they put in a skittle in vinegar? Or in Sprite? Or in water? Tell them that they will be setting up experiments to test what happens to skittles when exposed to 3 different kinds of liquids.
   0. Note that the students will be very excited they get to use candy for their experiment. Be sure to tell them that they are not allowed to eat the skittles. Safety is an important part of science, and we never eat lab materials or eat in the lab.

There will be clean Skittles and M&Ms to give two or three Skittles to each student after the lesson right before you leave.

Activity

This lesson does not include a demonstration performed up front by the volunteers because it is important for the students to make their own predictions before revealing what happens to the candy.

1. Show the students the materials (variables) that they can test and write out the list of variables on the board. They are going to work in pairs to design a unique experiment to test what happens to a single skittle and change one variable, the liquid.
2. Each pair will make their own prediction to test. For example: vinegar will dissolve off the color the fastest, sprite will create the most fizz, or blue skittles will lose their color the fastest.
3. Each pair of students should write their changed variable and their hypothesis on a sheet of paper before doing the experiment.

The classroom may have multiple English as a Second-Language (ESL) students that are unable to write down their variables and predictions. Simply write their variables down for them or skip that part. We want the science lessons to be fun, not stressful for these students.

1. Have a supply table to provide materials to each group after they write the variable they want to test (changed variable) and hypothesis.

Another good way of keeping track of their chosen variables is to write their variable for them on a piece of tape on their cups.

• There may be a lot of groups that want to test the same variable so tell them that you may have to assign them a different changed variable if too many groups choose to test the same variable.
• Some liquids dissolve the color from the skittles and other liquids dissolve the color and the skittle itself. It may take a few minutes to begin to see a change so if the students begin to get impatient make sure to tell the students that science takes time.
• If possible, give all groups the same colored skittle to reinforce the concept that all variables are the same except for the liquid.

1. After all the groups perform their experiment, ask the class what each liquid did to the skittle and if their results agree with their hypotheses.
2. Tell the class that they will now test to see if the same thing happens to M&Ms. The controlled variable now becomes the liquid and the changed variable is now the candy. Make sure to reinforce the topic that you should only change one variable in an experiment. So they will use the same liquid for their M&M that they used for their skittle.
3. After all the groups test their variable ask the groups if the same thing happened to the M&M that happened to the Skittle.

Demonstration (If time permits)

1. Do a demonstration of a skittle rainbow by placing Skittles in a circle on a paper dish and pouring water into the center (the students love seeing this):

Wrap-up

1. Emphasize the Main Ideas.
2. Ask them what future tests they could do to figure out what it is about the different liquids that makes the Skittle and M&M change?
   0. Is it the acidity/carbonation/sugar?
   1. How could we find out?
3. Ask them what they think would happen to other types of candy like candy corn or lollipop?
   0. Do you think they would react the same way?
4. Again, the focus is on experimental design and being able to have a reason for their questions and predictions.
5. Try to leave a few minutes at the end for students to ask you questions about the day’s lesson or random science questions or grad school. The students often have many questions.
6. Thank the teacher and students on your way out!

Packing List

• Lesson Plans
• Baggie of sharpies, tape, dry erase markers, pens
• Stack of Observation Sheets
• Clear plastic cups
• Skittles
• M&Ms
• Pitcher
• Sprite
• Carbonated water
• Vinegar
• Baking Soda
• Molecular Model of glucose and water

Main Ideas

• Objects move by way of a push/pull called a force.
• Friction and air resistance are other forces that can cause an object to slow down or stop.

Background

This is similar to how a real rocket operates (although a real rocket expels exhaust gasses instead of carbon dioxide). .

Sir Isaac Newton first presented his three laws of motion in the "Principia Mathematica Philosophiae Naturalis" in 1686. His third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A. Notice that the forces are exerted on different objects.

In aerospace engineering, the principle of action and reaction is very important. Newton's third law explains the generation of thrust by a rocket engine. In a rocket engine, hot exhaust gas is produced through the combustion of a fuel with an oxidizer. The hot exhaust gas flows through the rocket nozzle and is accelerated to the rear of the rocket. In re-action, a thrusting force is produced on the engine mount. The thrust accelerates the rocket as described by Newton's second law of motion.

Fun facts:

• Most real-world rockets are single-use. SpaceX was the first to reuse rocket boosters. See attached image.
• Newton’s law works on every moving object, not just rockets. When a cannon fires a cannonball, the cannon gets pushed backwards with equal force.

Introduction

1. Ask the students what they learned about the previous week’s activity and introduce today’s activity. Start off by talking about force and motion. What is a force? What can move something forward?

Lead them to the idea of propulsion, might have to use a more third grade friendly term like “push.”

2. The system they’ll be working with today is balloon rockets! We are going to see how changing different parts of our rocket system will affect how far our rocket flies. Ask the students how rockets usually move, then explain that today they will be using carbon dioxide to fuel their balloon rockets.

0. Ask the students if they know what carbon dioxide is.

Demonstration of Control Experiment

1. Show the students how to set up the string “race track.” Model and explain the different jobs that each person will do. Be sure that you try this out in workshop so that you can figure out the most efficient way to do this. The key is that you don’t want the regular balloons to go all the way to the end, because then you can’t really measure different distances. The amount of friction in the “race track” varies depending on your materials.
   1. Tie one end of the string to a chair, desk, or other support.
   2. Pull the other end of the string through the straw.
   3. Pull the string tightly and tie it to another support.
   4. Blow the balloon up (but don’t tie it). Pinch the end of the balloon and tape the balloon to the straw as shown above.
   5. Let the rocket fly and then measure how far it went
   6. Call up students to help you get two more measurements of the control, for a total of three.
      1. Make sure to blow the balloon up the same amount each time.
      2. Be sure you also talk about the importance of doing multiple trials. See if they remember why from previous lessons.

Activity Directions

1. Split the class into even groups so that one JHMI volunteer is in charge of a small group of students, then spread out throughout the classroom.

2. Each group will then choose one variable to change, and then see how it affects the distance that the balloon rocket travels. Discuss what variables could be changed. You could write the following list on the board to give them ideas.
   0. Type of yarn/string/fishing twine
   1. Amount of air in balloon
   2. Length of straw
   3. Weight of balloon (tape on washers or pennies)
   4. Angle of string
3. Have the students make hypotheses (written or verbally discussed as a group) about what they think will happen when they change their variable. Will the balloon travel farther than the control? Will the balloon fly faster or slower?
   0. The stopwatches are in the crates just as a back-up option. If all the balloons make it to the end, you could try timing “how long it takes to reach the end”, but I think that would be difficult to measure accurately.
4. Help the students set up their own race track and take multiple measurements (at least 3). Time permitting, choose another variable to change and repeat the experiment!

Wrap-up

1. Have the groups share the results of their experiments.
2. Emphasize the main ideas. As air rushes out of the balloon, it creates a forward motion called thrust. Thrust is a pushing force that comes from the energy of the balloon forcing the air out. Different sizes and shapes of balloon will create more or less thrust. In a real rocket, thrust is created by the force of burning rocket fuel as it blasts from the rockets engine – as the exhaust gasses blast down, the rocket goes up.
3. Ask the students what they learned and what they enjoyed about the lesson. Be sure to thank the teacher and class before you leave, and don’t forget to collect the feedback slip from the teacher.

Packing List

• Lesson Plans
• Baggie of sharpies, tape, dry erase markers, pens
• Stack of Observation Sheets
• String rolled around spools
• Yarn
• Fishing twine
• Jute
• Nylon
• Colored twine
• Straws
• Balloons
• Timers/stopwatches
• Measuring tapes
• Bag of pennies
• Tape
• Scissors

Main Ideas

• The sounds we hear travel in patterns called waves
• Wave features are related to audio and music concepts
• Sound requires matter to move, and materials transfer sound differently Background

Sound can be modeled in multiple ways, but in simplest form, we can describe sound as a wave, a dynamic disturbance, or displacement from a reference state (Fig 1.). Think about the water line in a fish tank, before (0) and after (A) a fish splashes the surface. Amplitude (A) is the distance from where the water line was initially (0) to either the top or the bottom of the wave. We often associate amplitude with volume, but volume is calculated using a logarithm of amplitude so while amplitude can be zero, the lowest volume value is negative infinity. The distance from one point on a wave to the same point on the next wave, is called the wavelength, however sound and music are usually measured by frequency, the number of times the entire wavelength passes in one second. If the graph in Fig. 1. is of 1 second, then this wave is a 1Hz wave. If it’s 100 seconds, then this is a 0.01Hz wave. We can see now that higher frequencies complete more cycles per second than lower ones, so how many seconds would this graph have to be to be 10Hz? 1000Hz? 10,000Hz?? How would the two sounds differ? Does frequency remind you of another way we describe sounds, like the ones instruments make?

Frequency is typically associated with pitch however pitch is more about interpretation rather than the sound itself. Frequency and pitch have harmonics, higher- and lower-sounding waves that are whole integer multiples of any single wave (i.e.,1x= 50Hz,2x= 100Hz,3x= 150Hz, etc.). In music, octaves are a form of harmonic that repeat every eight notes in a scale and are twice the frequency of the same note one octave below. Instruments produce large and small vibrations producing low- and high-sounding waves, respectively. One example, string instruments, use different size strings to make different notes.

Violins and other string instruments have thick and narrow strings to produce low and high notes, respectively. Violin and orchestra strings are particularly narrow compared to guitars or bass. This helps orchestral instruments produce such high frequency sounds, although a talented guitar player can perform a large range! Both players manipulate the length of their strings as they vibrate to produce higher and lower notes. The octave on a string instrument is at about the midpoint, and when a player places their finger here it creates a node, a place of no vibration. So we see that half of a wavelength produces a frequency twice as high or vice versa, and a higher pitch or note. This relationship holds for most sounds, large profiles are best for lower frequencies, and small profiles are best for the higher ones. So, if you want to get the most of our sound, you need multiple speakers! So how can they get all that bass in headphones?

Head- and earphone companies are known for sound quality, but if small speakers aren’t great for bass, where does the low end in my music come from? Some companies already put multiple speakers in their headphones. Firstly, it helps that the phones are so close to your ear, making everything more direct. To fit in or over the ear, the scale of these speakers must be quite small, but together they reproduce sounds that a single speaker couldn’t. There are also phones that don’t go over or in your ear at all, but instead rest on a bone just behind them. Isn’t that odd?? Bones can’t hear! Actually, sound travels through your bones much better than it does through the air! Have you ever been told to touch or listen to the ground to hear if a train is coming?

An important feature of sound is that it needs a medium. A medium is another word for material, particularly in which something moves or lives. Soil is a medium for plants, water, a medium for fish, etc. Because sound is made and travels by vibration, there must be something to vibrate for sound to get from its source to our ears. We’re used to hearing things through air, but it’s not as efficient as a solid object because its molecules are further apart. The more firmly the molecules in a medium are packed together, the better it transfers vibration if all other conditions are the same. For example, the notes we hear from a tuning fork, are only a few of the frequencies, or notes, it produces, and the bones in your head conduct sound well enough for you to hear them and more. In the right conditions, placing a

It’s odd that we can perceive some sounds better through parts of the body other than our ears, but this is exactly how many animals without visible ears hear. Snakes and fish are able to detect vibrations around them, especially large objects that could be predators or food! Remember that sound is a form of vibration, regardless of the source or medium. The molecules in the medium exchange energy as the vibration passes through them. If you think about how a slinky behaves when you stretch and compress it, then you have an idea of what this looks like.

Activity Materials

• Plastic and Styrofoam cups w/ holes in the bottom
• String, yarn, and/or plastic line
• Scissors (if necessary)
• Cups for water
• Soap
• Tuning Fork
• Slinky Activity Directions

1. Ask the students what they remember about the previous week’s activity and introduce today’s activity.
2. This week we’re going to learn how sounds are formed, what they need to travel, and how different materials respond to sound.
3. Briefly discuss with the class different types of musical instruments and how they work
   • Asking questions can help prompt discussion: “How does a guitar work, are there different kinds? What about singing? What makes all instruments similar?”
   • Point out some of the different ways sound is generated by groups of instruments (e.g., drums are hit or shaken, trumpets & flutes use air, guitars have strings.)
4. Let the students know that they’re going to begin by getting into groups and building a telephone with easy to find items.
   • How do telephones work?
   • How are telephones like/unlike instruments and other sound devices?

Activity Directions

1. Have the students start in pairs with two cups w/ holes and a length of string.
2. For each pair, instruct them to thread the string through the cups and put a knot in it, inside the cup. The String Telephone is complete! Have the pairs spread out and give them a test.
   • Start with a quiet voice that cannot be heard at a distance without the telephone. Then use the telephone with a loose line, speaking at the same volume. Tighten the line and try speaking again.
   • Can the students hear their partner when the string is loose? What about when it’s tight? Can you see the line vibrate? Are voices louder, or clearer through the phone?��What happens if someone touches or holds the string? Is there a distance where the phone doesn’t work?
   • Give the group a chance to try a different string or cup material, or a different length. Does sound travel any differently?
3. Using the slinky, have one student hold one end still, or tape it down. Stretch out the slinky a bit and give it a quick compression parallel to the direction of the stretch. What do you see?
   • You should see alternating areas of tight slinky, called compression, and loose slinky, called rarefaction.
   • As sound moves, it pushes air molecules which bump into each other, like marbles, or bumper cars. This bumping moves from the sound source to your ear where it bumps into your eardrum, causing small bones to vibrate, which your brain interprets as sound.
4. To show how the material sound moves through affects how we hear it, use the tuning fork to have the group “listen” through their heads instead of their ears
   • Strike the tuning fork across something firm, but not hard enough to make anything but the fork vibrate. You should be able to hear at least two notes. Now place the bottom of the fork on a students’ head as it vibrates and ask what they hear.
   • Because bone conducts sound so well, the vibrations travel through your skull to the inner ear. Because bone conducts sound better than air, the group might report hearing a third note, perhaps between the two they hear with their ears.
   • Bone conduction is good enough to aid people with hearing deficits. In some cases, it’s possible to restore lost hearing!
5. Squawking Cup (Optional if time)
   • We’re only able to hear sounds between 20-20,000 Hz, usually when we’re young or if our hearing is very good, but most of us use some type of amplifier to better project sounds in our daily lives. You can make a simple amplifier with just a single cup, string, and water.
   • String a piece of thread through a cup with a hole in the bottom, and tie off the end inside the cup.
   • Holding the cup right-side up in one and, hold the exposed string tightly between your thumb and first finger and give it a short quick tug, so the string slides through your fingers. What do you hear? What does it sound like without a cup?
   • While the group builds their speakers, add some water to two cups and a bit of soap to the other. What happens if your fingers are wet? What happens if your fingers are soapy?
   • We don’t always think of sound when we think of friction, but in some cases the relationship is more apparent. When a drag car speeds off the starting line and the wheels build up friction on the track, it makes a good bit of sound. The cup lets you hear the small friction sound in the string through the bottom of the cup, like a speaker.

Main Ideas

• We can use scale models to represent things that are really big or really small.
• Seasons happen because the Earth spins at an angle.
• Eclipses happen when the moon is between the sun and Earth and vice versa.

Background

The universe is much, much bigger than what we can see or even imagine. When you look up at night and see the stars, you are looking into history and seeing what those stars looked like millions upon millions of years ago. Our solar system is in the arm of the Milky Way Galaxy. Everything in our solar system orbits around the Sun. Our Sun is a star, a giant ball of fiery gas, so big that it pulls other objects in space into its gravitational orbit.

Our solar system contains

• 1 star: the Sun!
• 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune
• 5 dwarf planets: Pluto, Ceres, Eris, Makemake, and Haumea
• 181 moons (including our moon)
• 566,000 asteroids (rocky leftovers from the birth of our solar system)
• 3100 comets (made mostly of frozen methane, water, and ammonia that orbit our Sun)

Fun Facts about Our Solar System

• Right now, our planet is the only one we know of that supports life. But scientists think that there might be life elsewhere, like below the surface of Mars and clouds of Venus, or on the moons of Jupiter and Saturn.
• Our solar system is huge! The distance between the Sun and Neptune is about 2.8 billion miles.
• We think our solar system formed about 4.5 billion years ago.
• The Sun is so big that Earth could fit inside it over a million times!
• Venus is the brightest planet we see in our solar system, meaning that you can often see it from Earth without a telescope. It reflects enough light to cast its own shadows.
• Mars used to have water on its surface so scientists are trying to find out if it once supported life.
• Saturn has over 80 moons and the largest ring system!
• One year on Mercury is only 88 days while one year on Neptune is over 60,000 days–that’s 165 Earth years!
• You need 1000 Jupiters to fill the Sun, but you could fit 1300 Earths in each one!

Our solar system is so big it’s hard to comprehend it. Today we will make a scaled model of the solar system, learn about why seasons happen, and discover what an eclipse is.

Introduction

1. Ask the students what they remember about the previous activity and introduce today’s activity. Ask them if they can name any other planets in our solar system.
2. Everything in our solar system orbits around our Sun, which is actually a star. Ask the students how big the Sun is compared to Earth. How many of our planet would it take to fill up the Sun. (Answer: 1 million!)
3. How big is our solar system? Imagine you were driving a car at highway speed–60 miles an hour– from the Sun to Neptune. It would take you over 5,000 years to reach Neptune! But today we’re going to scale down the solar system to a more manageable size and learn some fun facts along the way.

Activity Directions

PART 1: A Distance Model of the Solar System

1. Work in groups of about 8 or 9–one student per planet.
2. Explain that a scale model is changing the size of something really big or really small but maintaining the proportions. For example, a Hot Wheels car is a scale model of a real car. Today we are going to create a scale model of the solar system. We will make the Sun and the planets much, much smaller but maintain their relative distances.
3. First we are going to see how big the solar system is! Have each student take an index card and assign each student to be the Sun or one of the eight planets.
4. Have the Sun stand at one end of the classroom. Explain that the Sun is a star and everything in the solar system orbits around the Sun.
5. Next up is Mercury, the closest planet to the Sun. Mercury can get really cold at night– -290 degrees F–and really hot during the day–800 degrees F! Have Mercury stand 1 step away from the Sun.
6. The next planet is Venus. This is the brightest planet we can see and third brightest object in the sky, you can often see it before sunset. Have Venus stand 2 steps away from the Sun.
7. Next is Earth, where we live. Life on Earth first appeared about 3.7 billion years ago! Have Earth stand 3 steps away from the Sun.
8. After Earth is Mars. Mars is called the red planet because the iron in its surface makes it look dusty red. Have Mars stand 4 steps from the Sun.
9. Next up is Jupiter. Jupiter is made of swirling liquids and gas in a constant storm. Have Jupiter stand 13 steps away from the Sun.
10. The next planet is Saturn. Saturn is surrounded by 82 moons and thirty rings. Have Saturn stand 25 steps from the Sun.
11. Next is Uranus (good luck with the pronunciation). This planet actually spins on its side. Have Uranus stand 50 steps from the Sun.
12. Last we have Neptune. Neptune is called an ice giant because it is very cold with super strong winds. Have Neptune stand 78 steps from the Sun.
13. Look at how far away Neptune is from the Sun. In our model one step is 36 million miles. Our solar system is really big!
14. If you have the space, point out that the planets orbit the sun. Have each student walk around the Sun trying to maintain their relative distances.

PART 2: A Size Model of the Solar System

1. Next we are going to compare the sizes of the planets! Hand out the solar system printouts to each student.
2. Students can color in each planet or just cut them out.
3. Have them arrange each planet in order–Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Compare the size of each planet to Earth.
4. Why isn’t the Sun included? If we included the Sun at this scale, it would be about 10 feet wide! That’s like two or three students stacked up!
5. Students can take their model home!

PART 3: Seasons and Eclipses

1. Dim the lights.
2. Hold up a globe. Tell the students that this represents the Earth.
3. Turn on a flashlight to represent the Sun. Have one student hold the flashlight in place. There is day, when the Earth faces the Sun and night, when it is turned away.
4. Ask the students why they think some places on Earth have day when others have night and vice versa. This is caused by the Earth spinning around.
5. What about the seasons? When it is summer, do they think the Earth is closer to the Sun or farther away? What about winter?
6. Seasons happen because the Earth spins at an angle. Note that the globe is tilted on its axis as it spins. Tilt the Earth at an angle and walk around the flashlight in a circle. Tell the students to focus on Baltimore, which is in the northern hemisphere.
7. We have winter when Baltimore is tilted away from the Sun and receives less sunlight so it is colder.
8. Walk ninety degrees counter-clockwise. Spring happens when both the top and bottom halves of the globe receive equal amounts of sunlight.
9. Walk ninety degrees counter-clockwise. Now it is summer in Baltimore since the northern hemisphere is tilted towards the Sun.
10. Walk ninety degrees counter-clockwise. The top and bottom halves of the globe have equal amounts of sunlight so it is the fall.
11. If there is time, explain what eclipses are. Hold up a smaller ball and tell the students that this represents the moon. When the moon is between the Sun and the Earth, it casts a shadow on the Earth’s surface. This is called a solar eclipse. When the Earth is between the Sun and the moon, it casts a shadow on the moon. This is called a lunar eclipse.

Wrap-up

1. Ask a few of the students to share what they learned and what they liked best about the lesson.
2. Emphasize the main ideas, and ask the students to share their results from each part of the experiment.
3. Check to see if there are any lingering questions.
4. Thank the teacher and class on your way out. Remember to get the feedback slip back from the teacher!

Packing List

• Lesson plans
• Index cards
• Scale model of the planets sheet
• Markers
• Globe
• Flashlight
• Smaller ball

Main Ideas

• DNA is the blueprint for life and contains instructions needed for all living things to grow and survive.
• DNA is stored in every cell and is also passed down from parents to children.
• Complicated science research procedures come from simple concepts.

Background

DNA is the blueprint of cells in all organisms. A cell is like a computer and DNA is like program code. Computers use 1s and 0s to store information while DNA uses A, T, C, and G, molecules to store information. Among humans, 99.9% of our DNA is identical (i.e. it’s just the 0.1% that accounts for our differences). There’s also similarity among species that might seem very different from us – i.e. Humans and mice share approximately 92% of their DNA (All mammals are quite similar genetically). And humans and yeast still share 26% of their DNA.

DNA is packaged and condensed to form chromosomes in cells. Most species are diploid, meaning they have two sets of chromosomes, one set of chromosomes is normally inherited from each parent. Polyploidy, a condition more common in plants, occurs when multiple pairs of chromosomes are present in the genetic component of an organism. Strawberry species and hybrids can be diploid, tetraploid, pentaploid, hexaploid, heptaploid, octoploid, or decaploid (having 2, 4, 5, 6, 7, 8, or 10 sets of the seven strawberry chromosomes, respectively).

Fun facts:

• Scientists know very little about the DNA code. Many research labs are trying to figure this out.
• Researchers at Johns Hopkins do this same DNA extraction procedure to isolate DNA for experiments.

Introduction

1. Introduce today’s activity (ex. “Today we’ll be looking at DNA which stands for deoxyribonucleic acid.”). Ask the students what they know about DNA. Mention that DNA contains the instructions necessary for organisms to grow and survive. Ask the students what color they think DNA is.
   1. Additional questions you can ask: What sorts of things have DNA? What does DNA��do? Where is DNA stored? What does DNA look like? How can we study DNA? What are some of the reasons that people are interested in DNA? What are some questions you have about DNA?
2. Show the DNA and talk about how these models don’t show the actual color of DNA. Ask the students if certain things have DNA: animal, plant, mushroom, rock, paper; ask them to raise their hands if they think there is DNA each respective thing. Answer: There is DNA in animals, trees, mushrooms. There is no DNA in rocks. There are DNA bits and pieces in paper but no strands of DNA remain intact after the paper-making process.
3. Say “Since all plants and animals have DNA and DNA contains the instructions for growth of organisms, what is it about DNA that causes plants and animals to be so different from each other?” Each plant and animal has a slightly different DNA code that instructs the plant/animal to grow and develop in a different way. You can introduce the analogy that every book has words and letters but the order of the words and letters (the code) is what makes one book very different from another.
4. After talking a bit about DNA, get prepared to guide the students through the strawberry DNA extraction! Mention that there are only a limited number of materials and that it is important to share. Also, we need to reuse these materials for future activities so ask the students to be careful with the materials. You can guide the students step-by-step through the process or have them follow the instructions on their own (depending on their ability level).

Activity Directions

1. The students will do the activity while you demonstrate each step up front. While this is more structured than we usually like to make our SiA activities, you can still encourage critical thinking by asking them questions about each step while you do it. i.e. What do they think the purpose of each step/ingredient is? How else could we accomplish that task? Etc…
   0. Also note that there are a lot of containers and measuring vessels in this activity. You’ll want to be really clear with the students about what step each thing is used for.

2. Making the DNA extraction buffer - Each table will make one batch of buffer to share. They will mix up the buffer in the plastic cup. One important point is that the graduated cylinders are ONLY used for measuring clear liquids (water and isopropyl alcohol).
   0. Combine the following ingredients in the large cup:
      0. 5 mL liquid detergent (measure in the narrow 15 mL centrifuge tubes)
      1. 0.75g salt (will probably be pre-measured in baggies)
      2. 45mL water

Stir gently so that the salt dissolves, but try not to create many bubbles. Then set this aside.

3. Extracting the DNA

• Take 1-2 strawberries – you want to have enough that they are about the same total volume as a golf ball.
• Remove the green sepals from the strawberries and place strawberries into a Ziploc bag and seal it shut. Squish for 30 seconds or so to squash the fruit without causing a bunch of foam to form. Students sometimes go a bit overboard here. Remind them that we don’t want to squish the strawberries so much that it will cause the DNA to shear/degrade.
• Add 10 mL DNA Extraction Buffer (measure again in the narrow centrifuge tube), and squish it for another minute. Try not to make a lot of foam.
  • Moisten a filter with a bit of water. Set the moistened filter in a funnel, and place it in the large test tube. Pour the strawberry and buffer mixture into the filter. Try not to squeeze the filter but you may be able to gently squeeze if the flow is really slow.
  • Once most of the liquid has made it through, put the filter and strawberry pulp in the trash.
  • Have the students record how many milliliters of strawberry liquid they have collected (using the markings on the tube it was collected in).
  • Next they need to measure out ice-cold 99% isopropyl alcohol. Students will need as much isopropyl alcohol as they have strawberry liquid. Measure it out in the graduated cylinders.

Note: For the activity to work properly, the isopropyl alcohol has to be really, really cold. It will be stored in the freezer until you pick up your crate. Make sure you remember to take it out of the freezer. Grab some ice as well to put in the Styrofoam cooler, so that the isopropyl stays on ice until the students use it.

• Then pour the alcohol CAREFULLY down the side of the tube with the strawberry liquid, so that it forms a separate layer on top of the strawberry liquid. Make sure not to mix the two liquids when you are pouring!
• Watch for about a minute. What do you see? You should see a white fluffy cloud at the interface between the two liquids. That’s DNA!
• Use the wooden skewer to pull the DNA out and transfer it into a small Eppendorf tube to take home. The fibers you see are thousands and millions of DNA strands.

The DNA collected between layers of alcohol on top and strawberry extract underneath. DNA is insoluble in alcohol so it precipitates.

Wrap-up

1. While the students are finishing up, ask them to clean up and to draw or write something interesting from today’s activity on a sticky note (we will use these sticky notes to make a collage of their notes). Once everyone is done you can ask a few volunteers to share their thoughts.
2. Reinforce the main ideas
3. Place DNA samples in microcentrifuge tubes for each student to take home.
4. Ask the students if they have any additional questions.
5. Thank the teacher and students on your way out!

Packing List

• Lesson Plans
• Baggie of sharpies, tape, dry erase markers, pens
• Stack of Observation Sheets
• Graduated cylinders
• Conical tube with measurement markings
• 1/8 teaspoon or scale
• Dish soap
• Salt
• Strawberries
• Test tubes
• Microcentrifuge tubes
• Cheese cloth, gauze, or coffee filters
• Funnels
• Wood skewers
• Ziploc sandwich bags
• 99% Isopropyl alcohol
• Plastic cups

Adapted from: and

Adapted from: Gonzaga SIA! Strawberry Extraction 3rd Grade

Main Ideas

• Acids and bases are important to basic chemistry, as are the methods of determining whether something is acidic or basic.
• Acids and bases are opposites and can neutralize one another.

Background

Red Cabbage contains a natural purple color molecule called anthocyanin. By boiling chopped up red cabbage (or in our case, soaking in isopropyl alcohol), you can isolate anthocyanin. Change in pH affects the color of anthocyanin which makes it a great pH indicator. See attached picture of the various chemical forms of anthocyanin. By adding acidic or basic additives, you can alter the color of the red cabbage anthocyanin extract and visualize pH change.

Fun facts:

• Many fruit and vegetable skins can be used as pH indicators. What might this mean for fruit changing color as it ripens? See attached picture of the various natural pH indicators.
• Researchers at Johns Hopkins use pH indicators all the time. Knowing the pH of a solution is very important for experiments and to determine the properties of a solution.

Introduction

1. Ask the students what they learned about the previous week’s activity and introduce today’s activity.
2. Ask the students if they know what an acid is and if they can think of any examples. What about a base?
3. Tell them that water is made up of two hydrogen molecules and one oxygen molecule. Sometimes water can get another H+ or lose an H+ making H3O+ or –OH. The amount of H+ or OH- is what makes a solution acidic or basic.
4. Ask them why they think it’s important to know if something is an acid or base.
5. Ask them how scientists test whether something is an acid or base? They use indicators! Tell them that’s what they’re going to be doing today.

Activity Directions

1. Split the class into groups, 3 students per group works best.
2. Give each group 3 clear plastic cups and have the students measure out 60 mL of the purple cabbage juice into each cup. Make sure each group has at least two medicine droppers. Distribute control acid and base reagents - vinegar and ammonia. Put a very small amount of each into plastic cups.
   • You may choose to control the distribution of ammonia a bit more by having the kids get a medicine dropper full directly from a volunteer.

3. With a medicine dropper, add vinegar to the first cup and stir. Observe the color change! The mixture should go from purple to red, showing us that vinegar is an acid.
4. With a medicine dropper, add ammonia to the second cup and stir. Observe the color change! The mixture should go from purple to blue, showing us that ammonia is a base.
5. Challenge the students to get their solutions back to the original purple color. Remind them that acids and bases are essentially “the opposite”. Using the medicine droppers, they can add either vinegar or ammonia to their cup, stirring until the color changes.
6. Introduce the other household acids and bases you brought along. Ask the students which ones they think are acids and which are bases.
7. In the third cup, the students can pick one of the household products to test. Make sure each group has a hypothesis about whether the substance is an acid or a base.

Wrap-up

1. Emphasize the main ideas about acids and bases. You can also reinforce the importance of having controls in an experiment, as we did with vinegar and ammonia here.
2. Have the students discuss their results of their household substance test.
3. Which types of substances were generally acids? Which were bases? Why do they think that is?
4. Did they need more of the substance to make the color change? Discuss the strength of acids and bases.
   • The acids and bases we think of as dangerous are called strong acids and bases.
   • You can introduce the pH scale here, showing how scientists “rank” how strong an acid or base is

5. Tell the students that they could try the same thing at home but instead of red cabbage juice they could use beet juice, red apple skin juice, or plum skin juice.

6. If there is any red cabbage juice remaining, divide it up into a bunch of microcentrifuge tubes and hand it out to students so that they can take a sample home with them to add an acid or base to it.
7. Thank the teacher and students on your way out!

Packing List

• Lesson Plans
• Baggie of sharpies, tape, dry erase markers, pens
• Stack of Observation Sheets
• Red Cabbage
• Rubbing Alcohol
• White Vinegar
• Household Ammonia
• Clear plastic cups
• Plastic Spoons
• Medicine Dropper
• Safety Goggles (if possible)
• Tupperware Containers
• Graduated cylinders
• Lemon juice
• Baking soda
• Sprite
• Toothpaste
• Dish soap

Adapted from “Red Cabbage Acid Test” on Education.com

Main Ideas

• Light travels in straight lines.
• Engineers who understand light can use this knowledge to build useful devices like cameras.

Background

A “pinhole camera” is a simple camera that uses a hole instead of a lens. Light passes through the pinhole and hits the other side of the device (where there is usually camera film). The image is “inverted” (i.e. flipped top-to-bottom and left-to-right).

Introduction

1. Ask the students what they learned about the previous week’s activity and introduce today’s activity.
2. Ask the students what they know about how cameras work.
3. If the students haven’t already talked about lenses, ask them what they know about lenses.
4. Explain the pinhole camera:
   0. Tell the students that light usually travels in a straight line.
   1. Show a diagram of a pinhole camera (e.g. the one with the tree shown above).
   2. Say that we can put a camera (or film) in the device to record the image. Or we can use a screen to see the image. SiA doesn’t use a camera to record the image, but we’ll still call the device a “pinhole camera”.
   3. Emphasize that the image will be flipped upside-down and left-to-right.

Activity Directions

1. Cut away the top and bottom of the cardboard box. (A volunteer should do this step.)
2. Tape the cereal box over one of the cut-away sides of the cardboard box. Make sure that light can’t get through cracks between the cereal and cardboard boxes!
3. Use the drill bit to make a hole in the center of the cereal box. Make the hole as round as possible.
4. Tape wax paper over the other open side of the box.
5. Look at the wax paper. You should see an image of what the pinhole points at. The image should be reflected up/down and left/right.
   0. The camera works best when the user (and the camera) are in a dark area looking towards a light area. E.g.you can stand in the back of a dark room and look at a window.
6. Move/rotate the camera and watch the image change. Have someone stand in front of the camera, so that their image is shown.
7. If there is time, do either/both of the additional demonstrations:
   0. Show light being separated by the prism. Explain that different colors of light can behave differently.
   1. Fill the cup ⅔ full of water. Stick the pencil in the water. Point out that the pencil looks like it bends at the waterline.

Wrap-up

1. Show the diagram of the pinhole camera (with the tree) again.
2. Thank the teacher and students on your way out!

Packing List

• Big image of camera diagram (probably the diagram with the tree)
• Wax paper
• Cardboard box (roughly 9” x 8” x 6”)
• Duct tape
• Part of cereal box (big enough to cover a side of the box)
• 7/64” drill bit
• Prism
• Clear cup (can be plastic)
• Pencil

Main Ideas

• A bridge must be strong enough to support its own structure and any cargo.
• Bridges are designed to be as efficient, economical and elegant as safely possible.
• There are six major designs of bridges: beam, arch, truss, suspension, cantilever and cable-stayed.

Background

There are six major designs of bridges. The beam bridge is the most common form. A beam carries vertical loads by bending. As the beam bridge bends, it undergoes horizontal compression on the top. At the same time, the bottom of the beam is subjected to horizontal tension. The supports carry the loads from the beam by compression vertically to the foundations.

A single-span truss bridge is like a simply supported beam because it carries vertical loads by bending. Bending leads to compression in the top chords (or horizontal members), tension in the bottom chords,

and either tension or compression in the vertical and diagonal members, depending on their orientation.

The arch bridge carries loads primarily by compression, which exerts on the foundation both vertical and horizontal forces. Arch foundations must therefore prevent both vertical settling and horizontal sliding.

A suspension bridge carries vertical loads through curved cables in tension. These loads are transferred both to the towers, which carry them by vertical compression to the ground, and to the anchorages, which must resist the inward and sometimes vertical pull of the cables.

A cantilever bridge is generally made with three spans, of which the outer spans are both anchored down at the shore and cantilever out over the channel to be crossed. The central span rests on the cantilevered arms extending from the outer spans; it carries vertical loads by tension forces in the lower chords and compression in the upper chords. The cantilevers carry their loads by tension in the upper chords and compression in the lower ones. Inner towers carry those forces by compression to the foundation, and outer towers carry the forces by tension to the far foundations.

Cable-stayed bridges carry the vertical main-span loads by nearly straight diagonal cables in tension. The towers transfer the cable forces to the foundations through vertical compression. The tensile forces in the cables also put the deck into horizontal compression.

When constructing a bridge, engineers can adjust the distance between supports in order to carry the load. Generally, the distance between supports is as short as possible, unless the bridge is constructed over water, where the foundation is less firm. Engineers also try to make bridges as efficient and economic as possible, by reducing the costs and the amount of materials used.

Introduction

1. Ask the students if they remember what they did last class and tell them that today they are going to be building bridges. What are some things that a bridge has to be able to do?
2. Introduce the ideas of forces, tension, and compression.
   0. Ask the students what forces are acting on a bridge. They may think of the weight of a car or truck, which comes from the force of gravity. What about something like wind?
   1. Ask the students if they know what the words tension and compression mean. It may be helpful to illustrate these ideas in terms of bridge bending with a slinky - rings far apart induces tension on one side while the side where the rings are pushed together is compressed.
3. Ask the students why it is important for a bridge to be safely constructed. What happens if a bridge cannot support its load?

Activity Directions

1. Give each student or group of students plastic straws, scissors to cut the straws, and sticky tack or tape to attach the straws. Give them 5-15 minutes (depending on your class) to design and construct their bridges.
2. Have the students test their bridges with a cup full of pennies. Are their bridges able to support the load? Give the students a matchbox car for a test drive across their bridge.
   0. If you want, this could be made into a contest by seeing which bridge can hold the most pennies.

Wrap-up

1. Ask the students to clean up.
2. Once everyone is done you can ask a few volunteers to share their thoughts.
3. Figure out which bridge designs were able to best support the cups full of pennies and the matchbox cars. Ask the students if they observed bridge bending when they built their straw bridges. Do we feel a bridge bend in real life?
4. Reinforce the main ideas:
   0. Bridges can bear loads through the opposing forces of tension and compression.
   1. There are six main ways to design bridges, some of which are more complicated than others.
5. Ask the students if they have any additional questions.
6. Thank the teacher and students on your way out!

Packing List

• Plastic straws
• Tape or sticky tack
• Scissors
• Plastic cups
• Pennies
• Match box cars
• Slinky

Adapted from:
Info:

Main Ideas

• Seeds are made by flowers
• Flowers have male parts (stamens) and female parts (carpels). The pollen from the stamen goes into the carpel (often with the help of pollinators) to fertilize the egg and create a plant seed.
• Students will explore the different parts of a flower, while also considering the importance of pollinators to ecosystems.

Introduction

1. Ask the students what they remember about the previous week’s activity and introduce today’s activity.
2. Ask the students: Can anyone tell us where plants come from? Someone will probably say seeds, in which case you can ask, But where do seeds come from? (If the students say “other plants”, try and get them to be more specific.) What part of the plant do seeds come from? Lead the discussion towards the idea that seeds are made by flowers. Does anyone know how that happens? Does the seed just randomly appear in the middle of the flower? (No… there are several steps that need to happen first.)
3. Many plants and flowers have “helpers” to assist them in making seeds. What are those helpers called? Who tends to visit flowers? The students may have had a unit on bees when they were in a younger grade, so they may know a fair amount about bees and pollination. Lead the discussion towards the idea that many different animals can act as pollinators. (Bees, flies, butterflies, birds, bats, and other animals can all be pollinators.)
4. Ask the students exactly what the pollinators do. (Pollinators help bring pollen to the egg cells in a plant. When the pollen connects with these egg cells and fertilizes them, a seed is formed that can grow up into a baby plant (so the seed has genes from both the pollen and the egg cell). Some plants can self-fertilize, but in either case they often need help moving the pollen to the stigma (which leads to the egg cell).)
   1. Pollinators often get the pollen “by accident”. They go to the flower to get nectar (a sugary liquid they like to eat). The pollinator may come to eat the nectar and also ends up getting the pollen on it. When it goes to the next flower, the pollen gets deposited on the carpel so that fertilization can take place. When the tiny egg inside is fertilized, then a seed is formed!
5. Flowers that rely on pollinators have big colorful petals and lure them to come with a reward of nectar. Some flowers have a sweet smell, but there are others that smell like rotting meat to attract animals that like rotting meat, like flies. Flowers that are pollinated by wind don’t have big showy flowers because they don’t have to spend the energy attracting something to come visit.
6. Show pictures of different flowers on document camera. Things to point out:
   0. The very large flower that smells like rotting meat to attract flies that pollinate it.
   1. Grasses have tiny little flowers on them (don’t need to be large or attract pollinators because they are wind pollinated).
   2. You can point out that some flowers are showy to attract pollinators’ attention and even have “nectar guide” markings that show the insect where to land and go for nectar.
7. Put up a diagram of the different parts of a flower that they will see. Flowers have a male part that makes pollen. This part is called a stamen. Flowers also have female parts called a carpel, which contains the stigma (where the pollen lands during fertilization), and the ovary (where the egg cells are contained at the base of the carpel). Point out the different parts on the diagram, and where the new seed will develop after fertilization. The flower they receive may look slightly different than this diagram, but it will have the same basic parts.

Activity Directions

** FYI: I don’t know exactly which species you will have in the classroom – it depends on what I find in the stores… You’ll most likely have lilies, tulips, and hopefully one other species (so that they can compare and contrast). Lilies have very distinct anatomy, but be aware that their pollen can stain (comes out with Shout).

1. Today we will be dissecting flowers to see what they look like and how they make seeds. There should be one flower per student, and they can dissect them either in a petri dish or on a sheet of scratch paper. Try to distribute the flowers so there are a variety of species at each table (so they can compare them). They can dissect them either in a petri dish or scratch paper.
   0. Make sure your crate has scratch paper!
2. To start, pull one petal off to look at the stuff inside. Draw a picture of the entire flower. Label the stamen (male parts), the carpel (female parts), and the petals. Make it a competition, ask the students to pretend that they are a scientist and draw the flower in the most realistic way possible.
3. Have the students find someone else who has a different kind of flower and compare and contrast the two.
4. Now pull off one of the stamens and draw it. Look at the little pieces of pollen with a magnifying glass and draw those as well.
5. Now pull off all of the stamens and all the petals. What you have left is the carpel. The top is where the pollen lands (called the stigma). If you touch it you can feel that it is a little sticky. Why do the students think it would be sticky? (so that the pollen will get caught there) The bottom part is where the little egg cell is. This is what becomes the seed after it is fertilized by pollen.
6. While all of the above is happening, set up the dissecting scopes some place that the students can take turns using them. Make a few cross section of the ovary with the razor blade (do NOT give it to the students) and look at the eggs inside. You can also put some pollen under the dissecting scope and look at it. If there’s time, you can also find other “cool things” for them to look at under the scope.
   0. During the workshop, talk about how to structure this part of the lesson with your��group. You may want to have students work on the discussion questions while their table waits for a turn at the dissecting scopes. If there’s extra down time while they wait, you could tell them to go back and add color to their drawings.

Emphasize that everyone should wash their hands after doing this. We don’t want students rubbing pollen in their eyes or noses, especially if they have allergies. Be especially careful with the lily pollen, since it can stain.

Wrap-up

1. Be sure to save 5 minutes at the end for a wrap up discussion. A few other things to think about:
2. Many people are concerned about the decline of bees due to colony collapse disorder. What effect could that have on plants? What effect could it have on us?
3. Ask if anyone observed lines or dots on their petals and what they might by for. These nectar guides act as a map showing insects where to find the nectar. You can mention that insects see color differently than we do (some see ultra-violet) so these markings could look totally different to them.
4. FYI regarding the worksheet questions: Flowers generally have more stamen because the more pollen they produce, the more likely it is that some of that pollen will get picked up and eventually end up coming into contact with a carpel and pollinating an egg.

Packing List

• Lesson Plans
• Baggie of sharpies, tape, dry erase markers, pens
• Stack of Observation Sheets
• Tweezers
• Toothpicks
• Magnifying glasses
• Flowers