Book 22 activities
Try it at home: 150 science activities from Book 22
Every question in A Million Whys Book 22, The Energy Expedition, ends with a "Think like a scientist" idea. Here they are in one place. Each one links to its question page, with the video and the full answer.
Expedition 1: Energy Is Everywhere (25)
1. What Exactly Is Energy?
Make a list of ten things you saw today that changed or moved. Next to each, write where you think its energy came from.
2. How Can You Tell Energy Is There When You Can’t See It?
Walk around a room and point to five places where energy is at work. Say what changed in each place.
3. What Kinds of Energy Are There?
Draw a table with six squares. Label them motion, heat, light, sound, electrical, and chemical, and draw one example in each.
4. How Is Stored Energy Different From Moving Energy?
Hold a ball at shoulder height and then drop it. Say when it has stored energy and when it has moving energy.
5. Why Can Energy Never Be Made or Destroyed?
Rub your hands together fast for ten seconds. Say what kind of energy you started with, and what kind you ended up with.
6. Where Does a Ball’s Energy Go When It Stops Rolling?
Roll a ball across carpet and across a smooth floor. Which one stops sooner? Where did its energy go?
7. What Does It Mean to “Use Up” Energy?
Clap your hands hard twenty times, then feel your palms. Where did some of the motion energy from your arms end up?
8. Why Does a Stretched Rubber Band Hold Energy?
With a grown-up nearby, stretch a rubber band a little and then a lot, and shoot a paper wad at a soft target on the floor, away from people and pets. Which stretch sends the wad farther? Never aim at faces.
Do this with a grown-up9. Why Does a Book on a High Shelf Hold Energy?
Drop a sponge from a low spot and then from higher up onto a tray of sand. Compare the dents. Higher means more energy.
10. What Is the Energy Hiding in Food, Fuel, and Batteries?
Look at the label on a food package with a grown-up. Find the “Calories” line. That number shows how much energy is stored in one serving.
Do this with a grown-up11. Why Do Scientists Call Heat Energy on the Move?
Hold an ice cube in your hand for ten seconds. Which way does the energy move: from your hand to the ice, or from the ice to your hand?
12. How Does Energy Change From One Form Into Another?
Choose a toy or a gadget with a grown-up. Draw arrows that show what forms of energy go in and what forms come out.
Do this with a grown-up13. How Can You Follow Energy From the Sun to Your Toast?
Draw an energy chain for your breakfast. Start with the Sun and write each step, including your body’s use of it.
14. Why Do Machines Waste Some Energy?
Touch a warm laptop charger or phone charger with a grown-up. The warmth is wasted energy. Write down how warm it feels from one to ten.
Do this with a grown-up15. What Does “Work” Mean in Science?
Lift a book from the floor to a table. Then lift two books. Which one took more work, and why?
16. What Is Power, and How Is It Different From Energy?
Walk up a few stairs slowly, then run up. Say which time your legs worked harder and which time you used more power.
17. How Do We Count Energy?
Look at an electricity bill with a grown-up. Find where it says kWh and write the number.
Do this with a grown-up18. How Did James Joule Show That Motion Can Turn Into Heat?
With a grown-up, bend a paper clip back and forth ten times quickly, then touch the bend gently. Why does it feel warm?
Do this with a grown-up19. Do Rocks and Mountains Have Energy?
Put a dark rock in sunlight for an hour. Touch it with one fingertip first, carefully. What kind of energy did it gain?
20. Why Do People Say “Save Energy” If Energy Never Disappears?
Write three things at home you could do to use less useful energy, like turning off a light when you leave a room.
21. What Happens to Energy When Two Things Bump?
Line up eight dominoes and tip the first one. Watch how energy travels down the line, like a relay race.
22. Why Does It Take Energy to Make Something Move, Even a Little?
With a grown-up, push an empty shopping cart, then push it again with some heavy items in it. Which push felt harder to start?
Do this with a grown-up23. Is There Energy Inside Atoms?
Draw an atom as a small ball with a speck in the middle. Label the electrons moving around and the nucleus in the center.
24. Can a Wave Carry Energy Without Carrying Stuff Along?
Tie a rope to a chair and flick the free end up and down. Watch the wave move along the rope while the rope stays in place.
25. Why Can’t We Build a Machine That Runs Forever?
Swing a pendulum made of a string and a washer and watch it slow down. Write one reason it can’t go forever.
Expedition 2: Energy in Motion (25)
26. What Is Kinetic Energy, the Energy of Motion?
Roll a toy car slowly into a paper cup, then roll it faster. Measure how far the cup slides each time.
27. Why Does a Diver on a High Board Hold Potential Energy?
Stretch a Slinky or a spring from a pen, with a grown-up nearby. Hold one end and let go of the other. Watch what happens. Describe what happens to the stored energy. Share your results with someone you love.
Do this with a grown-up28. Why Does Speed Matter So Much for Moving Energy?
Roll a toy car down a ramp from a low start, then a high start, into a block. Measure how far the block moves each time.
29. Why Does a Heavy Truck Have So Much More Moving Energy than a Bicycle?
Roll a marble and a larger, heavier ball down the same ramp into a cup. Compare how far each pushes the cup.
30. How Does a Roller Coaster Trade Height for Speed?
Bend a foam pipe cover into a track with two hills and roll a marble. Does it make it over the second hill if it is taller than the first?
31. Why Does a Pendulum Swing Back and Forth?
Make a pendulum from string and a washer. Time ten swings with a short string and ten with a long one. Which swings slower?
32. Why Does a Ball Speed Up Faster on a Steeper Hill?
Prop a board at a gentle angle and then a steep angle. Time a toy car rolling down each one. Which one is quicker?
33. Where Does a Squashed Spring’s Stored Energy Go When You Let Go?
Push a spring toy down on a table and let it go. Count how many bounces it makes before stopping.
34. How Does a Wind-Up Toy Store Energy?
If you have a wind-up toy, count how many turns of the key it takes. Does more winding make it go longer?
35. Why Does Falling From Higher Up Hurt More?
Drop a marble onto flattened play dough from three heights. Measure the dent each time.
36. How Does a Moving Bowling Ball Pass Energy to the Pins?
Roll a ball into a group of empty plastic cups. Try a bigger ball and a smaller ball. Count how many cups fall.
37. Why Can One Domino Knock Over a Whole Row?
Line up a row of dominoes, then try setting them closer and farther apart. What spacing makes the chain work best?
38. Where Does the Energy Come From When You Jump?
Stand next to a wall and jump as high as you can with your knees bent, then with your knees stiff. Ask a friend to mark each height.
39. How Does a Toy Catapult Launch Things?
With a grown-up, build a craft-stick catapult and launch a pom-pom. Measure how far it goes with a small bend and a big bend.
Do this with a grown-up40. How Does a Cyclist Use Energy to Climb a Hill and Then Coast?
Ride a bike with a helmet on a gentle slope with a grown-up. Count how many seconds you coast before slowing down.
Do this with a grown-up41. Where Does the Energy Go When Bike Brakes Stop You?
Rub a rubber eraser hard on paper for ten seconds. Feel the eraser and the paper with a fingertip. Notice any warmth. What is the warmth made from? Then tell a friend what you found out.
42. How Do Electric and Hybrid Cars Save Energy While Braking?
Draw a car going downhill. Add arrows showing energy going from the wheels into the battery.
Do this with a grown-up43. How Does a Flywheel Store Energy?
With a grown-up, spin a bicycle wheel upside down. Count how many seconds it keeps spinning on its own.
Do this with a grown-up44. How Does a Hand-Crank Flashlight Work Without Batteries?
Crank a hand-crank flashlight for thirty seconds and time how long it glows. Does more cranking give more light?
45. How Does a Yo-Yo Store Spinning Energy?
Play with a yo-yo and notice how the spinning slows. Watch the first bounce. Watch the third bounce. Does it climb as high on the third bounce as on the first? Share your results with someone you love.
46. How Does a Balloon Rocket Use Stored Energy?
Thread a straw onto a string, tape a balloon to the straw, and let it go. Measure how far it travels with a little air and a full balloon.
47. Why Does a Pogo Stick Make You Bounce?
Hop on one foot a few times and feel your leg muscles and tendons spring. Count how many hops you can do without stopping.
48. How Does a Zipline Turn Height Into Speed?
Hang a string between a high and low point and slide a paper cup down it. Mark where it goes fastest.
49. Why Is a Heavy Box Harder to Push than an Empty One?
Use a rubber band to pull a shoebox across the floor with and without books inside. Measure how far the rubber band stretches.
50. How Do Helmets and Padding Soak Up Moving Energy?
Drop a marble onto a hard table. Listen to the sound and watch the bounce. Now drop it onto a folded towel. Compare the sound and the bounce. Then explain what you learned to a friend.
Expedition 3: Sun, Heat & Light (25)
51. How Does the Sun’s Energy Cross Empty Space to Reach Us?
Hold your hand near, but not touching, a lamp that has been on for a minute with a grown-up. Feel the warmth reaching you through the air without touching.
Do this with a grown-up52. What Makes the Sun Give Off So Much Energy?
Draw the Sun with a glowing core in the middle. Add arrows showing energy moving outward to the surface and then into space.
53. How Much of the Sun’s Energy Does Earth Actually Catch?
Hold a small ball two arm lengths away from a flashlight in a dark room. See how little of the light lands on the ball compared to the whole beam.
54. How Can Heat Travel From Place to Place?
Choose a cup of warm water. Find an example of each: conduction (hold the cup), convection (steam rising), radiation (warmth felt from the side).
Do this with a grown-up55. Which Holds More Heat: a Cup of Hot Tea or a Tub of Warm Water?
With a grown-up, put a small amount of warm (not hot) tap water in a cup and a large amount of warm tap water in a bowl. Predict which one will melt a pile of ice cubes faster.
Do this with a grown-up56. How Does a Blanket Keep You Warm If It Makes No Heat?
Wrap one warm water bottle in a towel and leave another bottle unwrapped. After 20 minutes, check which stays warmer with a grown-up.
Do this with a grown-up57. How Does a Leaf Turn Sunshine Into Food?
With permission, cover half of one leaf on a houseplant with a small piece of foil for a week. Peek under it at the end. Does the covered half look different from the half that got light?
58. How Is a Solar Water Heater Different From a Solar Panel?
Put a black bag and a clear bag of water in the sun for an hour. Touch them carefully with a fingertip to check which is warmer. Wear a hat and sunscreen.
59. What Is Infrared Light?
Point your phone camera at a TV remote, with a grown-up. Press a button on the remote. Look at the screen. Many phone cameras can show the infrared flash. Then tell a friend what you found out.
Do this with a grown-up60. Why Does a Parked Car Get So Hot with the Windows Closed?
With a grown-up, put a thermometer in a clear jar with a lid. Put another thermometer outside the jar in the sun. Compare the readings after fifteen minutes. Never put living things in a closed car or jar. Tell a grown-up what you discover!
Do this with a grown-up61. Why Do Very Hot Things Glow?
Look at pictures of glowing metal in a blacksmith’s shop. Match the colors to temperatures: red is cooler, white is hotter.
Do this with a grown-up62. Why Does Sand Heat Up Faster than Water?
Fill one cup with sand and another with water. Set them in the sun and measure each temperature every ten minutes. Touch the cups with a fingertip first, and wear a hat in the Sun.
63. How Does the Sun’s Energy Keep Water Moving Around the Planet?
Put a small amount of water in a clear tray and leave it in a sunny window. Mark the level in the morning and the evening.
64. What Invisible Rays Does the Sun Send Us?
Tape a coin onto dark construction paper and leave it in a sunny window for a week. Compare the paper under the coin with the rest.
65. How Much Power Does Sunshine Bring to One Square Meter?
Measure a square meter on the floor with tape. Imagine ten bulbs shining on it. That is how much solar power lands there.
Do this with a grown-up66. How Did People Long Ago Put Sunshine to Work?
Draw a house with big windows on the sunny side and small windows on the shady side. Add arrows for sunlight and warmth.
67. How Much Power Does a Solar Panel Lose When Clouds Roll In?
Use a small solar-powered calculator. Cover half of its solar panel with your hand. See if it still works. Then cover the whole panel. Write down what you notice, and share it with a grown-up.
Do this with a grown-up68. How Does a Thermos Keep Soup Warm?
Fill a thermos and a regular cup with warm water. Check each temperature after one hour with a grown-up.
Do this with a grown-up69. How Does a Hot-Water Radiator Warm a Room?
With a grown-up, hold a strip of tissue paper near a warm radiator from a safe distance. Does it move up? That shows air rising.
Do this with a grown-up70. What Happens to Light When Something Swallows It?
Put a black sock and a white sock in the sun for twenty minutes. Feel each one with your hand. Notice which feels warmer. Which sock got warmer? Keep asking why, and keep exploring!
71. What Are the Tiny Packets of Energy in a Sunbeam?
Draw a flashlight beam as a stream of tiny dots. Use blue dots for high energy and red dots for lower energy.
72. How Much Heat Does a Person Give Off?
Hold a thermometer in the air of a quiet room and again after a group has been there for half an hour. See whether the room warmed up.
73. How Hot Is the Sun’s Surface, and How Hot Is Its Core?
Make a bar graph comparing the temperature of a freezer, boiling water, the Sun’s surface, and the Sun’s core. Use a different scale for each.
Do this with a grown-up74. How Do Astronauts Keep Cool in Space Where There Is No Air?
Wrap one warm water bottle in shiny foil and another in dark paper. After thirty minutes, check which kept more heat.
75. Why Doesn’t Earth Keep Getting Hotter If the Sun Keeps Sending Energy?
Fill a bathtub in your imagination. The tap is the Sun, the drain is heat going out. Draw it level, higher, and lower.
Expedition 4: Food, Fuel & Bodies (25)
76. How Do Scientists Find Out How Much Energy Is in a Peanut?
With a grown-up, watch a video of a peanut calorimeter experiment. Write down how the water’s temperature changes.
Do this with a grown-up77. Why Is the Calorie on a Food Label Spelled with a Capital C?
Look at three food labels. Rank the foods from the most Calories to the fewest. Does the order surprise you?
78. How Does Your Body Get Energy Out of Food?
Draw the path food takes from your mouth to your cells, using arrows. Label where it is broken down and where the nutrients enter your blood.
79. How Do Your Cells Burn Food Without Fire?
Breathe out onto a cold mirror and see the fog form. Some of that water vapor came from your cells burning food.
80. Why Does Your Body Make Its Own Heat?
Rub your hands hard for twenty seconds, then hold them against your cheeks. Describe how the warmth feels.
81. How Do Muscles Use Food Energy to Move?
Squeeze a tennis ball or sponge for thirty seconds. Notice when your hand starts to feel tired. That is your muscle getting tired.
82. Why Do Small Animals Eat So Much for Their Size?
Compare animals on a list: mouse, cat, dog, human, horse, elephant. Guess which eats the most food per pound of body weight.
83. Why Do Reptiles Need Less Food than Mammals?
Compare a list of things a warm-blooded animal and a cold-blooded animal do to stay warm or cool.
84. Where Does Energy Go as It Moves Up a Food Chain?
Draw an energy pyramid with grass at the bottom, rabbit in the middle, and fox on top. Make each level smaller than the one below.
85. Why Do Ecosystems Have So Many More Plants than Meat-Eaters?
In a park, count plants, plant-eating insects, and bird hunters you notice in ten minutes. Which group is largest?
86. How Do Plants Store the Energy They Make?
A grown-up can put one drop of iodine on a potato slice and keep the bottle. Watch, but don’t touch, as it turns dark blue-black, showing starch. Do not eat it, and wash your hands afterward.
Do this with a grown-up87. What Makes Fat Such a Good Energy Bank?
Look at nuts and seeds on a food label. Find the fat content and the Calories. Why do you think nuts have so many?
88. How Does Hibernating Save Energy?
Draw two charts of heartbeat, one for an awake squirrel and one for a hibernating squirrel. Use different line heights.
89. What Is Metabolism?
Count your breaths for one minute while sitting still. Then jump up and down for thirty seconds and count again. What changed?
90. Where Does the Energy in Coal and Oil Come From?
Draw a timeline from ancient swamps to a modern power plant. Add the Sun at the beginning.
91. Why Does Burning Release Stored Energy?
Look around your home with a grown-up and make a list of five things that burn fuel, like a furnace, a gas stove, or a car.
Do this with a grown-up92. Why Do Liquid Fuels Pack So Much Energy?
Compare the weight of one AA battery to the weight of a cup of water. Imagine carrying thousands of batteries instead of a cup of fuel.
Do this with a grown-up93. How Does a Car Engine Turn Fuel Into Motion?
Draw a piston moving up and down in a cylinder. Add arrows to show how it turns a crank.
94. What Is Biofuel?
Look at a gas pump with a grown-up. Find the sticker that says how much ethanol the fuel may contain.
Do this with a grown-up95. How Did People First Use Wood to Cook and Stay Warm?
Draw an energy chain for a wood stove: Sun, tree, firewood, flame, warm room.
Do this with a grown-up96. How Can Rotting Food Scraps Make Fuel?
Write a list of kitchen scraps that could go into a biogas tank. Draw a simple picture of the tank and pipe.
97. How Can an Eel’s Body Make Electric Shocks?
Stack three toy batteries in a drawing to show how many small voltages add up to a bigger one. Draw an eel next to it.
98. Why Can a Cheetah Sprint Fast but Not for Long?
Run in place as fast as you can for ten seconds. Then jog for one minute. Which could you keep up longer? Notice how your body warms up. Then explain what you learned to a friend.
99. Why Do Migrating Birds Eat So Much Before a Long Trip?
Weigh a small bag of marbles, then add some. Imagine how a bird’s weight changes before migrating.
100. How Do Deep-Sea Animals Get by with So Little Food?
Imagine a deep-sea animal. Draw it with a big mouth, glowing lure, and slow tail. Write how each feature saves energy.
Expedition 5: Power for Our World (25)
101. How Does a Power Plant Make Electricity for a Whole Town?
Hold a pinwheel in front of a fan. It spins like a turbine. Draw what would happen if it were connected to a generator.
102. What Is the Power Grid?
Draw a map with a power plant, towers, a neighborhood, and your home. Connect them with lines to show the grid.
103. Why Do Long-Distance Power Lines Use Such High Voltage?
Look for the big metal towers or tall poles near your neighborhood. Draw one and label the wires. Never go near them.
104. Why Do Many Power Plants Burn Fuels Like Coal and Gas?
Make a list of three good things and three problems about burning fuel for power. Compare it with a friend’s list.
105. What Makes an Energy Source Renewable?
Sort cards or a list into renewable and not renewable: wind, coal, sunshine, oil, waves, wood, tides.
106. How Does a Wind Turbine Turn Wind Into Electricity?
Make a pinwheel and blow on it from different angles. Which angle spins it fastest?
107. Why Do Wind Farms Put Their Turbines So High Up?
With a grown-up, use blunt scissors to cut two paper pinwheels, one with short blades and one with long blades. Ask the grown-up to push in the pin. Spin them with a fan. Which one catches more wind?
Do this with a grown-up108. How Do Rooftop Solar Panels Share Power with the Grid?
Look at a map of your neighborhood. Count how many roofs you see that might have solar panels, and which direction they face.
109. How Does a Tidal Power Station Use the Ocean?
Fill a bathtub or basin and let water slosh in and out through a small paddle wheel. Watch how it spins as the water moves.
110. How Can Ocean Waves Make Electricity?
Float a cork in a pan of water and make waves with your hand. Notice how the cork moves up and down. Imagine it turning a generator.
111. What Is Nuclear Energy, and How Does a Power Plant Use It?
Draw the steps in a nuclear power plant: fission, heat, steam, turbine, generator, wires. Label each one.
Do this with a grown-up112. What Happens to Solar and Wind Power When the Sun Sets or the Wind Stops?
Make a chart of a day with the sun’s power curve and the wind’s power curve. See when each is strongest.
113. How Can We Store Extra Electricity?
Match each storage idea with a toy. Try a stretched rubber band, a wound-up spring, and a raised ball. Think about which one is like a battery. Explain your match to a friend. Then tell a friend what you found out.
Do this with a grown-up114. How Does Pumped Storage Work Like a Giant Water Battery?
Use two buckets, one on a sturdy table outdoors and one on the ground. Pour water from the high one through a funnel to turn a pinwheel.
Do this with a grown-up115. What Is a Kilowatt-Hour on an Electricity Bill?
Find the wattage on a lamp or small appliance with a grown-up. Do not unplug anything yourself. Figure out how many hours it would take to use one kilowatt-hour. Hint: divide one thousand by the wattage. Write down what you notice, and share it with a grown-up.
Do this with a grown-up116. Why Does the Electricity in a Town Sometimes Go Out?
Make an emergency kit with a flashlight, spare batteries, and a radio. Show it to your family.
117. How Do Solar Lamps and Small Grids Bring Light to Faraway Places?
Charge a solar garden light in the sun for a day. See how long it glows after dark.
118. How Is an Electric Car Charged, and Where Does That Energy Come From?
Draw the path of energy from a power plant to the wheels of an electric car. Compare it with the path for a gasoline car.
119. Can Hydrogen Be a Clean Fuel?
Look at a bottle of water and imagine splitting it into hydrogen and oxygen. Draw how the two gases join back together to make water.
120. How Much Electricity Can You Make by Pedaling?
At a science center or with a hand-crank toy, try to power a small light. Notice how tired your muscles get.
121. Why Do Solar Panels in Canada Face South?
Use a compass to find south in your yard. Look for roofs or windows that face that way.
122. What Is That Gray Can on the Power Pole?
Take a walk around your block with a grown-up and count the transformers you can spot on poles or in boxes.
Do this with a grown-up123. Why Do Some Power Plants Have Giant Cooling Towers?
Ask a grown-up to pour hot water into a cup and hold a cold plate above it, while you keep your face and hands at arm’s length. Watch the vapor turn to droplets on the plate, like a cooling tower’s cloud.
Do this with a grown-up124. Why Does Electricity Use Go Up in the Evening?
Keep a list for one evening of everything in your home that is turned on from 5 to 8 p.m. Which items could wait until later?
125. What Is the Trade-Off with Each Energy Source?
Make a table with four sources of energy. For each one, write one good thing and one challenge.
Expedition 6: Smart Ways to Save Energy (25)
126. What Does Energy Efficiency Mean?
Compare two bulbs’ labels, one LED and one old type, with a grown-up. How much light does each give, and how many watts does each use?
Do this with a grown-up127. What Do Energy Star and EnerGuide Labels Tell Us?
Look for a label on a fridge or washer at home or in a store. Write down how much energy it says it uses in a year.
128. Why Do Some Devices Use Power Even When They Are Turned Off?
Walk around your home with a grown-up and spot all the little lights that stay on. Count how many there are.
Do this with a grown-up129. Why Do Windows Let So Much Heat Escape in Winter?
Feel a window on a cold day, then feel a nearby wall. Which is colder? Why do you think that is?
130. How Does Insulation Keep a House Cozy?
With a grown-up, wrap one cup of warm water in a wool sock. Leave another cup of warm water bare. Check the temperatures after twenty minutes. Which one stayed warmer? Keep asking why, and keep exploring!
Do this with a grown-up131. How Does a Thermostat Know When to Turn the Heat On?
Find the thermostat in your home. Ask a grown-up what it is set to, and check what the room thermometer says.
Do this with a grown-up132. How Does a Heat Pump Move Heat Instead of Making It?
From a safe distance, never touching the fan, feel the warm air near the back of a fridge or from an air conditioner’s outdoor unit with a grown-up. Notice that heat is being moved, not just made.
Do this with a grown-up133. Why Does Hanging Laundry Outside Save Energy?
Hang a wet washcloth outside and another one indoors. Check which one dries first.
Do this with a grown-up134. What Happens If the Fridge Door Stays Open?
Tape a thermometer inside the fridge. Check it before and after the door is open for a minute (with a grown-up’s permission).
Do this with a grown-up135. Why Does Putting a Lid on a Pot Save Energy?
Watch (don’t touch) as a grown-up boils the same amount of water in two pots, one with a lid and one without. Which boils first?
Do this with a grown-up136. Does Taking a Shorter Shower Really Save Energy?
Time your shower for a week. Try to make it one minute shorter and see how much water you may save.
137. How Can Trees Around a House Save Energy?
On a sunny day, measure how warm the ground feels in the shade and in the sunshine. Compare them.
138. What Is Passive Solar Design?
Observe a sunny room. Where does the sunlight fall in the morning and afternoon? What warms up?
139. Is Biking More Energy-Efficient than Driving?
With a grown-up, plan a short trip to a nearby place by bike or on foot. How long would it take?
Do this with a grown-up140. How Can You Find Drafts in Your Home?
Walk around your home with a feather or thin tissue and find three places where air leaks.
141. Which Energy-Saving Habits Matter Most?
Pick three habits that your family could try for one month. Make a chart to check them off.
142. How Do Motion-Sensor Lights Save Energy?
Find a motion-sensor light. Walk toward it slowly and then quickly. When does it turn on?
143. Why Does a Phone Charger Feel Warm?
Touch a charger when it is plugged in but not charging, then when charging. Where does it feel warmer? Ask a grown-up first.
Do this with a grown-up144. Why Does Recycling an Aluminum Can Save Energy?
Count the cans your family uses in a week. Imagine how much energy you save if they all get recycled.
145. What New Energy Ideas Are Scientists Testing?
Imagine a new way to make energy. Draw it and explain to a friend how it would work.
146. How Can Your Class Run an Energy-Saving Project?
Make a checklist for your classroom. Include lights, projectors, computers, and windows.
147. Can Footsteps on a Special Floor Make Electricity?
Estimate how many steps you take in a day. If each step made a tiny bit of energy, would it add up?
148. Which Things in a Home Use the Most Energy?
List ten things at home that use energy. Rank them from your best guess of most to least. Check with a grown-up.
Do this with a grown-up149. Why Do Small Energy Savings Add Up?
Calculate how many hours of light you save by turning off a 10-watt bulb for an hour a day for a year.
Do this with a grown-up150. What Are the Big Ideas to Remember About Energy?
Write your own “Energy is…” sentence. Share it with a friend, and spot the energy changes around you today.