ACT Science

A weather notebook recorded rainfall in millimeters on four April days. Monday brought 6, Tuesday brought 11, Wednesday brought 4, and Thursday brought 9.

A city bus driver tallied riders boarding at the first morning stop. Monday had 28 riders, Tuesday had 35, Wednesday had 21, and Thursday had 32.

A baker wrote down the temperature of a cookie tray in degrees Celsius as it cooled on a rack. At 0 minutes the tray was 90 degrees, at 2 minutes it was 74, at 4 minutes it was 62, and at 6 minutes it was 54.

Four bean plants in a kitchen window were measured in centimeters after three weeks. Pot 1 was 8 centimeters tall, Pot 2 was 15, Pot 3 was 12, and Pot 4 was 19.

A garden bin received kitchen scraps, and the gardener weighed each week's addition in kilograms. Week 1 was 3 kilograms, Week 2 was 5, Week 3 was 4, and Week 4 was 8.

A workshop timed how many minutes four paint samples took to dry to the touch. Red took 40 minutes, blue took 25, green took 55, and yellow took 30.

A gardener read soil moisture as a percent in four beds on the same morning. Bed A was 20 percent, Bed B was 35 percent, Bed C was 50 percent, and Bed D was 28 percent.

A kitchen note tracked one bowl of bread dough. The dough was 4 centimeters high at the start, 6 centimeters after 20 minutes, 9 centimeters after 40 minutes, and 12 centimeters after 60 minutes.

A weather vane log listed wind speed in kilometers per hour. At 8 a.m. the wind was 12, at 10 a.m. it was 18, at noon it was 15, and at 2 p.m. it was 24.

A gardener planted 20 seeds from each of four packets and counted sprouts. Basil produced 16 sprouts, dill produced 10, parsley produced 14, and chives produced 8.

A workshop bin held leftover nails sorted by length. There were 40 nails that were 2 centimeters long, 25 that were 3 centimeters, 55 that were 4 centimeters, and 15 that were 5 centimeters.

A cook measured water from a kettle as it sat uncovered. The water was 100 degrees Celsius at 0 minutes, 82 degrees at 5 minutes, 70 degrees at 10 minutes, and 61 degrees at 15 minutes.

A transit log listed liters of fuel used by one bus on four routes. Route 1 used 18 liters, Route 2 used 24, Route 3 used 12, and Route 4 used 30.

A garden diary listed the lowest temperature, in degrees Celsius, on four nights. Night 1 fell to 4, Night 2 fell to -2, Night 3 fell to 1, and Night 4 fell to -5.

A woodshop swept sawdust into bags and recorded the mass in grams. Monday's bag was 120 grams, Tuesday's was 80, Wednesday's was 200, and Thursday's was 160.

A kitchen shelf held finished jam. There were 12 strawberry jars, 8 peach jars, 15 apricot jars, and 6 plum jars.

A rider checked one bicycle tire. The pressure was 32 psi in the morning, 28 psi after the ride, 36 psi just after a pump, and 34 psi the next morning.

A gardener measured mulch depth in centimeters. Bed A had 3 centimeters, Bed B had 6, Bed C had 5, and Bed D had 9.

A baker recorded oven temperature while it heated. The oven was 20 degrees Celsius at minute 0, 80 degrees at minute 2, 140 degrees at minute 4, and 180 degrees at minute 6.

Shirts on one line were timed until they felt dry. The cotton shirt took 50 minutes, the linen shirt took 40, the wool shirt took 70, and the nylon shirt took 30.

A yard notebook listed grams of seed eaten from a feeder. Day 1 lost 30 grams, Day 2 lost 45 grams, Day 3 lost 20 grams, and Day 4 lost 35 grams.

A homeowner counted water droplets on four windows at dawn. The north window had 22 droplets, the east window had 9, the south window had 14, and the west window had 18.

A pottery workshop weighed four wet lumps of the same clay. Lump 1 was 400 grams, Lump 2 was 250 grams, Lump 3 was 500 grams, and Lump 4 was 350 grams.

A sidewalk gauge recorded new snow from four storms, in centimeters. Storm A left 6, Storm B left 2, Storm C left 8, and Storm D left 4.

A bus heater log listed cabin temperature at four stops, in degrees Celsius. Stop 1 was 10 degrees, Stop 2 was 14, Stop 3 was 17, and Stop 4 was 16.

Four matching tomato rows received different fertilizer amounts, and the harvest was weighed in kilograms. The row with none yielded 4 kilograms, the low amount yielded 6, the medium amount yielded 9, and the high amount yielded 8.

A kitchen timed how long one ice cube lasted in each of four cold drinks. The cube in water lasted 12 minutes, the cube in lemonade lasted 9, the cube in iced tea lasted 15, and the cube in milk lasted 18.

A student counted steps from the bus stop to the shop door. Monday was 840 steps, Tuesday was 910, Wednesday was 760, and Thursday was 880.

A candle was measured as it burned. It started at 20 centimeters, was 16 centimeters after 1 hour, 12 centimeters after 2 hours, and 8 centimeters after 3 hours.

A path was built in four sections, and the gardener counted bags of gravel. Section 1 used 7 bags, Section 2 used 3, Section 3 used 5, and Section 4 used 9.

A bowl of soup sat on a counter. It was 70 degrees Celsius at minute 0, 55 degrees at minute 10, 46 degrees at minute 20, and 40 degrees at minute 30.

A small coop log listed eggs gathered over four days. Monday had 5 eggs, Tuesday had 3, Wednesday had 6, and Thursday had 4.

A workshop counted sheets left in four grit stacks. The 80-grit stack had 6 sheets, the 120-grit stack had 10, the 220-grit stack had 4, and the 320-grit stack had 8.

A weather page listed the outdoor temperature at sunrise on four days, in degrees Celsius. Day 1 was 7, Day 2 was 11, Day 3 was 5, and Day 4 was 9.

A baker checked four trays of 12 muffins each and counted how many rose above the liner. Tray 1 had 9, Tray 2 had 6, Tray 3 had 12, and Tray 4 had 3.

A rain barrel started the morning with 40 liters. After Bed 1 was watered, 32 liters remained. After Bed 2, 26 liters remained. After Bed 3, 18 liters remained.

A rider noted how many minutes late four morning buses were. Route A was 2 minutes late, Route B was 7 minutes late, Route C was 0 minutes late, and Route D was 5 minutes late.

Four jars of honey were weighed in grams. Jar 1 was 340 grams, Jar 2 was 360 grams, Jar 3 was 300 grams, and Jar 4 was 320 grams.

A yard crew bagged leaves and recorded the mass in kilograms. Week 1 was 2 kilograms, Week 2 was 5, Week 3 was 3, and Week 4 was 6.

A gardener planted the same bean variety in four pots of the same soil. Each pot received the same amount of water each day and sat on the same windowsill. The only difference was planting depth: 1 centimeter, 2 centimeters, 4 centimeters, or 6 centimeters. After two weeks, the seeds planted at 2 centimeters had the most leaves.

A cook steeped the same tea in four cups. The water in every cup started at the same temperature, and each cup received the same mass of leaves. The cups sat for 1 minute, 2 minutes, 3 minutes, and 4 minutes. The tea that steeped longer looked darker.

A student rolled the same toy car, with the same mass, down one wooden ramp. The ramp was set at 10 degrees, then 20 degrees, then 30 degrees. From 10 degrees the car rolled 40 centimeters along the floor, from 20 degrees it rolled 70 centimeters, and from 30 degrees it rolled 95 centimeters.

A baker made four loaves from the same dough recipe, in the same size of pan, at the same oven temperature. The only change was the yeast: 1 teaspoon, 2 teaspoons, 3 teaspoons, or 4 teaspoons. The loaf with 3 teaspoons rose the highest. The loaf with 4 teaspoons rose less than the one with 3.

Four identical jars of hot water started at 80 degrees Celsius and sat in the same room for 20 minutes. Jar A had no wrap and ended at 50 degrees. Jar B, wrapped in a cotton towel, ended at 60 degrees. Jar C, in one wool sock, ended at 68 degrees. Jar D, in two wool socks, ended at 72 degrees.

A gardener grew four basil plants in the same soil and gave them the same amount of water. Plant 1 received 2 hours of sun and grew to 8 centimeters. Plant 2 received 4 hours and grew to 12 centimeters. Plant 3 received 6 hours and grew to 15 centimeters. Plant 4 received 8 hours and grew to 14 centimeters.

In a still workshop, a student dropped a light washer and a heavy washer from the same height at the same moment. The heavy washer had more mass. Both washers hit the floor together.

Four iron nails of the same size sat in the same shed for two weeks. Nail 1 stayed dry. Nail 2 was wiped with water once. Nail 3 was kept damp under a wet cloth. Nail 4 sat in a cup of water. Rust was least on Nail 1 and greatest on Nail 4.

On a kitchen counter, the same volume of vinegar was poured into four glasses. The glasses then received 1 teaspoon, 2 teaspoons, 3 teaspoons, or 4 teaspoons of baking soda. The glass with 4 teaspoons foamed the highest.

A gardener built two piles from the same kitchen scraps and set both in the same corner of the yard. One pile was turned every day. The other pile was not turned. After a week, the turned pile was warmer.

Four brands of paper towel were used to wipe up the same volume of spilled water from the same countertop. Brand A needed 3 sheets, Brand B needed 2 sheets, Brand C needed 1 sheet, and Brand D needed 4 sheets.

A cook heated four identical pots, one at a time, on the same burner. Each pot held the same volume of water. The pots received 0 grams, 5 grams, 10 grams, or 15 grams of table salt. The water with more salt began bubbling at a higher temperature.

A walker crossed the same wet tile with the same stride in four shoes. The shoes differed only in tread depth: 1 millimeter, 2 millimeters, 3 millimeters, or 4 millimeters. The 1-millimeter tread slipped. The 4-millimeter tread did not slip.

Four lettuce rows received the same water. At midday, leaves with no shade cloth were 32 degrees Celsius. Leaves under one layer were 29 degrees, leaves under two layers were 26 degrees, and leaves under three layers were 24 degrees.

A workshop used one magnet and a paper clip. With no paper between them, the clip lifted. It also lifted through 1 sheet and through 2 sheets. Through 4 sheets, the clip did not lift.

A baker baked four cakes from the same batter, at the same oven temperature, for the same time. One pan was bare metal, one was glass, one was dark metal, and one was silicone. The dark-metal cake browned the most on the bottom.

A driver tested the same bus on the same dry lot. Each run began at the same speed. Tire pressure was set to 20 psi, then 25 psi, then 30 psi, then 35 psi. The driver recorded how far the bus rolled after the brake pedal was pressed.

Four identical ferns received the same volume of water at each watering, in the same light and the same size of pot. One fern was watered every day, one every 3 days, one every 5 days, and one every 7 days. The fern watered every day turned yellow. The fern watered every 3 days stayed the greenest.

A student slid blocks of the same mass down a ramp set at the same angle and the same height. The sliding face was bare wood, waxed wood, sandpaper, or rubber. The waxed block reached the bottom first. The rubber block was the slowest.

A kitchen popped four batches of the same popcorn. The amount of oil and the heat setting stayed the same. Kernels were heated for 2 minutes, 3 minutes, 4 minutes, or 5 minutes. The 2-minute batch had many unpopped kernels. The 5-minute batch had burnt pieces. The 3-minute batch had the most edible popped kernels.

Four glasses held the same volume of water and the same mass of sugar. Each glass was stirred for the same time. The water temperatures were 10, 30, 50, and 70 degrees Celsius. Less undissolved sugar remained as the water got hotter.

A marble left the same ramp and then crossed one of four surfaces. It rolled 90 centimeters on bare wood, 40 centimeters on a cotton towel, 25 centimeters on sandpaper, and 15 centimeters on a rubber mat. The ramp height was not changed.

Four squares of the same dyed cloth were watched for two weeks. One hung outside the window in the strongest light and faded the most. One hung behind the clear glass. One hung behind a white curtain. One stayed in a closed drawer in the same room and faded the least.

A rider used the same bicycle on the same flat path and pedaled at the same cadence. Only the gear changed, from gear 1 to gear 2, gear 3, and gear 4. A higher gear number moved the bicycle farther on each pedal stroke and felt harder at the start.

Bean seeds of the same variety were grown in the same soil with the same water. Seeds by a window bent toward the glass. Seeds in a dark box grew straight up.

A mason mixed four batches from the same concrete recipe in the same mixer. One batch was left dry. The others were kept damp under plastic for 1 day, 3 days, or 7 days. All four were scratched after 7 days. The batch kept damp for 7 days was the hardest to scratch. The dry batch scratched most easily.

In a dark room, one lamp stood still. Globe A was upright. Globe B was tilted. Each globe was turned through a full year at the same distance from the lamp. On Globe B, one hemisphere received the stronger light for part of the turn, and the other hemisphere received it later. Globe A did not switch which hemisphere received the stronger light.

A cook heated four pots of the same strawberry pulp for the same time. The pots received 0 grams, 50 grams, 100 grams, or 150 grams of sugar. The pot with 150 grams set the firmest gel. The pot with 0 grams stayed runny.

A student struck the same bell in the same way four times. A friend listened at 5 meters, then at 10 meters, then at 20 meters, and then at 40 meters. The friend said the sound was faintest at 40 meters.

Four boards cut from the same pine plank were stained from the same can. One board received 1 coat, one received 2 coats, one received 3 coats, and one received 4 coats. After drying, the board with 4 coats was the darkest.

A student fitted the same balloon over the mouth of one empty bottle. The bottle was set in water at 5 degrees Celsius, then 20 degrees, then 40 degrees, then 60 degrees. The balloon stood tallest on the 60-degree bottle and stayed limp on the 5-degree bottle.

Two rain barrels sat side by side and started with the same rainwater. One barrel had a lid. The other was open to the sun. After two weeks, the open barrel had a green film and the lidded barrel stayed clear.

A workshop pendulum kept a string length of 40 centimeters. The bob was changed among 50 grams, 100 grams, 150 grams, and 200 grams. The time for ten swings stayed about the same for every mass.

Four identical greasy tiles were scrubbed with sponges of the same brand. One sponge was dry, one was wet with water only, one was wet with a little dish soap, and one was wet with a lot of dish soap. The sponge with a little soap cleared its tile fastest. The dry sponge cleared almost none of the grease.

Text 1: Summer is warmer because Earth is closer to the Sun then. The shorter distance lets more sunlight arrive, and that is the cause of the hot season.

Text 2: Earth's tilt points one hemisphere toward the Sun during that hemisphere's summer. The tilted hemisphere gets more direct light and longer days. Earth's distance from the Sun changes only a little over the year and does not cause the seasons.

A neighbor said the Moon's monthly phases happen because Earth's shadow covers part of the Moon. A sky guide replied that the phases come from the Moon's position relative to the Sun, so viewers see different portions of the sunlit half. The guide added that Earth's shadow on the Moon is a lunar eclipse, which is uncommon and darkens a full Moon, not the regular change from crescent to full.

A child said a heavy rock must hit the ground before a light pebble if both are dropped together, because the rock has more mass. A teacher dropped them from the same height. They landed together. The teacher said that when air resistance is too small to matter, extra mass does not make an object fall faster.

Text 1: The compost smells because the bin is too dry. Dry scraps cannot break down, so they sit and turn sour.

Text 2: The smell started after the lid was sealed tight. The same scraps in an open pile did not smell this way. A tight lid can leave the pile short of fresh air.

A custodian said salt melts sidewalk ice because the salt is hotter than the ice. A science note said the salt lowers the temperature at which the water on the ice freezes, so the ice can turn to liquid even while the air stays below 0 degrees Celsius. The note did not say the salt arrives hot.

A rider said the bus windows fogged because cold air leaked in from outside. The driver said the fog was on the inside of the glass and appeared after many damp coats filled the warm bus. Moisture from the coats met the cold glass and turned into tiny drops.

Text 1: The tomato leaves wilted because the soil dried out. The top of the soil was pale and cracked, and the leaves recovered after a deep watering.

Text 2: The leaves wilted because of a fungus. Watering will not help, and the pale soil is only dust from the path.

A homeowner said a thicker sweater always keeps a person warmer outdoors, no matter the wind. A hiker replied that wind can strip away the warm air a loose sweater holds. On a windy day, the hiker's thin wind shell over a light layer felt warmer than a thick loose sweater worn alone.

A cook said a rolling boil cooks pasta faster because the water is hotter than water at a slow boil. A kitchen note said that, at the same air pressure, boiling water stays at the same temperature whether it boils slowly or fast. A faster boil does not raise the water's temperature. It can only drive water off as steam sooner.

Text 1: The nails rusted because they were left in the rain. Water on iron starts rust, and the dry nails in the toolbox stayed shiny.

Text 2: The nails rusted because they are a cheap alloy that rusts in air alone. Nails of that alloy left in a dry toolbox still showed rust spots, so rain is not required.

A baker said the bread failed to rise because the kitchen was too cold for the yeast. The same dough later rose after the bowl was set near a warm oven. No new yeast was added.

Someone said moonlight is light the Moon creates, like a dim lamp of its own. A guide said the Moon has no such lamp. The bright part is the side facing the Sun, and that part goes dark in a lunar eclipse when Earth blocks the sunlight headed for the Moon.

Text 1: Fewer birds came because the seed was stale. Fresh seed in the same feeder brought the flock back the next day.

Text 2: Fewer birds came because a hawk perched nearby. The seed was already fresh, and the birds returned only after the hawk left.

A camper said a large log floats because the whole log is lighter than a small stone. A note said the log floats because its mass for its size is less than that of water, while the stone's mass for its size is greater than that of water. A tiny stone still sinks, and a huge log still floats.

A renter said water on a cold glass of lemonade must have leaked through the glass. A friend wiped the outside dry. New drops formed while the lemonade level stayed the same. The friend said water vapor in the room air had turned to liquid on the cold glass.

Text 1: The sidewalk cracked because tree roots lifted it. The crack follows the root line, and the slab is higher on the tree side.

Text 2: The sidewalk cracked because water in a joint froze and expanded. No root runs under this slab, and the two sides of the crack are the same height.

A driver said the bus battery failed on a cold morning because the cold ate the metal plates overnight. A mechanic said the cold slowed the chemical reaction inside the battery, so it could not push as much current at startup. After the same battery warmed in the shop, it started the engine. No parts were replaced.

A student said a flagpole's shadow at local noon is the same length on every day of the year. A schoolyard chart showed a short noon shadow in June and a long noon shadow in December. The student had ignored the change in the Sun's height at noon.

Text 1: The kettle boils sooner on the small burner because that flame is hotter. A hotter flame makes the water reach a higher temperature before it boils.

Text 2: The kettle boils sooner on the small burner because less heat escapes around a flame that fits the pot. At the same air pressure, the water still boils at the same temperature. The time to boil can change, but the boiling temperature does not.

A gardener said mulch cools summer soil only because the mulch is white. A trial covered one bed with dark mulch and left the next bed bare. Both beds received the same sun. At midday, the mulched soil was cooler than the bare soil.

A child said an echo in a stairwell is a second person copying the shout. A parent said the shout bounced off the far wall and came back. When blankets covered that wall, the echo faded. The shout itself was made the same way.

Text 1: The fern dropped leaves because it stood in a dark hall. Moving it to a bright window stopped the leaf drop, and the soil stayed moist the whole time.

Text 2: The fern dropped leaves because the soil was too wet. The hall was already bright, and the dropping stopped only after watering was cut back.

Someone said a magnet sticks to every metal. A workshop tried the magnet on iron screws, aluminum foil, copper wire, and a steel washer. It stuck to the screws and the washer. It did not stick to the foil or the wire.

A roommate said bread molds only when it is left in the dark. Two slices from the same loaf were kept equally moist overnight. One slice sat on a bright counter. The other sat in a closed bread box. Fuzzy spots appeared on both slices.

Text 1: The steps iced over because the porch light melted snow that then refroze. The light was on, and the ice sits in a patch under the lamp.

Text 2: The steps iced over because water dripping from the roof landed there. The lamp was off all night, and the ice lines up with the drip groove in the gutter.

A cook said food cooks faster in a covered heavy pot because the pot metal adds heat of its own. A note said a tight lid traps steam, the pressure rises, and water then boils at a higher temperature than in an open pot. The pot does not create heat. The stove still supplies the heat.

A parent said dryer socks cling because the dryer turns them into magnets like a fridge magnet. A note said tumbling pulls electric charge apart onto different fabrics, and unlike charges attract, so the socks cling. A fridge magnet stuck to the dryer door, but it did not stick to the socks.

Text 1: The seedlings leaned because the window was their only light. They bent toward the glass, and they grew straight after the pots were turned a quarter turn each morning.

Text 2: The seedlings leaned because the pots were tipped. The soil surface was slanted, and the lean matched that slant even on a shelf with no window.

A walker said morning dew falls from the sky like a light rain. A field note said dew forms when the grass cools overnight and water vapor in the air turns to liquid on the cold blades. The rain gauge stayed empty on mornings when the grass was soaked with dew.

A cook said a copper-bottom pot heats soup faster because copper is already hotter than steel before the stove is lit. A test started a copper-bottom pot and a steel pot at the same room temperature, on the same burner, with the same volume of soup. The copper-bottom pot reached a simmer first.

Text 1: The south walk melted first because the concrete is dark. Dark surfaces take in more sunlight. A light-colored board laid on that walk stayed icy longer than the bare dark concrete beside it.

Text 2: The south walk melted first because a buried steam pipe runs under it. An equally dark walk on the north side stayed icy, and the south walk melted even under a light-colored board.

A flat sheet of paper and a book were dropped together, and the book hit first. A student said this happened because heavier objects fall faster. The teacher crumpled that sheet into a tight ball and dropped the book and the paper ball together from the same height. They landed together. The teacher said the flat sheet had been slowed by air, not left behind because it had less mass.

A student said eggshells fizz in vinegar and that the fizz is a gas. Two jars sat on the counter. One held vinegar and crushed shell. The other held water and the same kind of shell. Bubbles rose only in the vinegar jar. The water jar stayed still.

Text 1: The bus took longer to stop because the road was wet. The same bus, at the same speed, stopped in a shorter distance on a dry stretch of that road the same afternoon.

Text 2: The bus took longer to stop because the brake pads were worn. It also stopped long on a dry road, and no wet-road comparison was made.