Matter and Energy
A student places four objects into a container of water. The student observes that a wooden block floats, a metal bolt sinks quickly, a plastic bottle cap floats, and a glass marble sinks.
Which statement best explains why the metal bolt sinks while the wooden block floats?
A. The metal bolt has more mass than the wooden block, so it always sinks in water.
B. The wooden block has more volume than the metal bolt, so it floats.
C. The metal bolt is more dense than water, while the wooden block is less dense than water.
D. The wooden block contains air, which causes it to sink more slowly than metal.
C. The metal bolt is more dense than water, while the wooden block is less dense than water.
A student uses a ramp to roll a ball downhill. The ball starts at the top with stored energy, then speeds up as it moves down the ramp. After reaching the bottom, the ball rolls across the floor and slowly comes to a stop.
Which statement best describes the energy changes in this system?
A. The ball’s energy disappears when it reaches the bottom of the ramp.
B. The ball’s stored energy changes into motion energy, which decreases due to friction.
C. The ball creates new energy as it moves down the ramp and across the floor.
D. The ramp pushes energy into the ball, making it stop at the bottom.
B. The ball’s stored energy changes into motion energy, which decreases due to friction.
A student observes a hillside over several months. After a heavy rainstorm, pieces of rock break off the hillside and are carried by running water into a nearby stream. Later, the water slows down and the rocks settle at the bottom of the stream bed.
Which statement best describes the processes in order?
A. Deposition breaks rocks apart, erosion moves the rocks, and weathering builds new landforms.
B. Weathering breaks rocks apart, erosion moves the sediments, and deposition drops them in a new location.
C. Erosion breaks rocks apart, deposition moves them, and weathering forms new rocks.
D. Weathering moves rocks downhill, erosion builds landforms, and deposition causes rain to fall.
B. Weathering breaks rocks apart, erosion moves the sediments, and deposition drops them in a new location.
In a desert ecosystem, a food chain is shown:
Cactus → Mouse → Snake → Hawk
If the mouse population suddenly increases, which outcome is most likely?
A. The cactus population will decrease because more mice will eat more cactus.
B. The snake population will decrease because there will be fewer hawks available.
C. The hawk population will increase because hawks will eat more cactus.
D. The cactus population will increase because mice will stop eating snakes.
A. The cactus population will decrease because more mice will eat more cactus.
A student adds a second light bulb to a simple circuit powered by one battery. After the second bulb is added, both bulbs become dimmer than before.
Which statement best explains why the bulbs became dimmer?
A. The battery created more electrical energy for each bulb in the circuit.
B. The electric current was shared between more parts in the circuit.
C. The wires prevented electricity from reaching the second bulb.
D. The added bulb caused the battery to stop producing electric current.
B. The electric current was shared between more parts in the circuit.
A student rolls a toy car across three different surfaces: smooth tile, carpet, and sandpaper. The car travels farthest on tile and stops quickly on sandpaper.
Which statement best explains the difference in how far the car travels?
A. The car gains energy when moving across rough surfaces, causing it to stop sooner.
B. Gravity is stronger on tile than on carpet or sandpaper, so the car moves farther.
C. Rough surfaces increase friction, which slows the car down more quickly than smooth surfaces.
D. Smooth surfaces create more force against the car, making it stop faster than rough surfaces.
C. Rough surfaces increase friction, which slows the car down more quickly than smooth surfaces.
A student observes the Moon over several nights and notices that it changes from a thin crescent to a full Moon and then back to a crescent. The student also learns that the Moon does not produce its own light.
Which statement best explains why the Moon appears to change shape over time?
A. The Moon actually changes shape as it orbits Earth, growing and shrinking each night.
B. Earth’s shadow covers different parts of the Moon each night, causing its shape to change.
C. Different amounts of sunlight reflect off the Moon as it moves around Earth.
D. The Moon moves closer and farther from Earth, making it appear to change shape.
C. Different amounts of sunlight reflect off the Moon as it moves around Earth.
A student observes four animal behaviors:
A baby sea turtle moves toward the ocean immediately after hatching.
A dog learns to sit when it hears a verbal command.
A spider builds a web without being taught.
A parrot learns to say words after hearing humans repeat them.
Which statement best describes the difference between inherited and learned behaviors?
A. Inherited behaviors are always more complex than learned behaviors and require training to appear.
B. Inherited behaviors are behaviors animals copy from other animals, while learned behaviors are instincts present at birth.
C. Inherited behaviors only happen in young animals, while learned behaviors only happen in adults.
D. Inherited behaviors are present at birth, while learned behaviors are developed through experience or practice.
D. Inherited behaviors are present at birth, while learned behaviors are developed through experience or practice.
A student mixes four different materials with water. After stirring each mixture for 2 minutes, the student observes the results. The sand settles to the bottom of the cup, the salt can no longer be seen, the cooking oil forms a layer on top of the water, and the iron filings stick together and sink.
Which material most likely dissolved in the water?
A. Sand
B. Salt
C. Cooking oil
D. Iron filings
B) Salt
A student places a pencil in a clear glass of water. The pencil appears bent at the point where it enters the water. The student also notices that a flashlight beam bouncing off a mirror changes direction at the same angle it hits the mirror.
Which statement best explains BOTH observations?
A. Light bends when it passes into a new material, and it bounces off smooth surfaces at equal angles.
B. Light is created by water and mirrors when objects are placed near them.
C. Light always travels in straight lines and does not change direction in different materials.
D. Light slows down only in mirrors, causing objects in water to appear larger.
A. Light bends when it passes into a new material, and it bounces off smooth surfaces at equal angles.
A city is planning a new energy project. Leaders are comparing wind energy and coal as possible sources of electricity. They are trying to choose a source that is sustainable and better for long-term environmental health.
Which statement best describes how these energy sources compare?
A. Wind energy is nonrenewable because it depends on weather conditions, while coal is renewable because it is found underground.
B. Wind energy is a renewable resource that can be naturally replenished, while coal is a nonrenewable resource that is limited and forms over a very long time.
C. Both wind energy and coal are renewable because they can both be used to generate electricity repeatedly.
D. Coal is renewable because new coal forms quickly, while wind energy is nonrenewable because it can stop blowing at times.
B. Wind energy is a renewable resource that can be naturally replenished, while coal is a nonrenewable resource that is limited and forms over a very long time.
A student studies a cactus that lives in a hot, dry desert. The cactus has thick, fleshy stems, sharp spines instead of leaves, and a waxy outer covering.
Which statement best explains how these structures help the cactus survive in its environment?
A. The spines help the cactus collect more rainwater, while the stems release extra water into the air.
B. The waxy covering helps the cactus absorb more sunlight, while the spines help it grow faster.
C. The thick stems store water, the spines reduce water loss and protect the plant, and the waxy coating helps prevent water from evaporating.
D. The cactus relies on its spines to perform photosynthesis because it has no stems or leaves.
C. The thick stems store water, the spines reduce water loss and protect the plant, and the waxy coating helps prevent water from evaporating.
A student sprays perfume into one corner of a large room. A few minutes later, people across the room can smell the perfume even though they are far away from where it was sprayed.
Which statement best explains why the smell spread throughout the room?
A. Gas particles move freely and spread out to fill the available space.
B. Gas particles remain packed closely together in one area of the room.
C. Gas particles sink because gases are heavier than air.
D. Gas particles stop moving after they are released into the air.
A) Gas particles move freely and spread out to fill the available space.
A student places a ringing alarm clock inside a sealed plastic container. The student notices that the sound becomes much quieter outside the container, even though the clock is still ringing at the same volume inside.
Which statement best explains why the sound is quieter outside the container?
A. Sound waves stop moving when they hit a solid object, so no sound can escape the container.
B. The plastic container creates new sound waves that cancel out the alarm completely.
C. Sound energy is stored inside the air and cannot move through any material except empty space.
D. Some sound energy is transferred into vibrations of the container, so less sound energy travels into the air outside.
D. Some sound energy is transferred into vibrations of the container, so less sound energy travels into the air outside.
A student observes a weather map showing a large area of warm, moist air moving toward a region where the air is cooler and drier. The map also shows clouds forming along the boundary where the air masses meet.
Which prediction is most likely correct based on these observations?
A. The weather will become clear and dry because clouds prevent precipitation from forming.
B. The weather will remain unchanged because air masses do not affect each other when they meet.
C. The weather will become colder and wind will stop as the air masses mix evenly.
D. The weather will likely bring clouds and possible precipitation as the air masses interact.
D. The weather will likely bring clouds and possible precipitation as the air masses interact.
A student observes that hummingbirds have long, thin, tube-shaped beaks. The student learns that hummingbirds feed on nectar found deep inside flowers.
Which statement best explains how the structure of a hummingbird’s beak helps it survive?
A. The beak is strong and flat, allowing the hummingbird to crush seeds and nuts easily.
B. The beak is long and tube-shaped, allowing the hummingbird to reach nectar inside flowers.
C. The beak is short and wide, allowing the hummingbird to catch insects in the air.
D. The beak is curved like a hook, allowing the hummingbird to tear bark from trees.
B. The beak is long and tube-shaped, allowing the hummingbird to reach nectar inside flowers.
A student is testing four different circuit designs using one battery, one bulb, and connecting wires. Only one design causes the bulb to light.
Which statement best explains why the bulb lights in that circuit?
A. The wires stored electrical energy until the bulb was full of current.
B. The bulb created its own electric current after being connected to the battery.
C. The battery pushed electricity into the bulb even though the circuit was not complete.
D. The battery transferred energy through a closed circuit that allowed electric current to flow continuously.
D. The battery transferred energy through a closed circuit that allowed electric current to flow continuously.
A student places a metal spoon and a wooden spoon into a cup of hot water at the same time. After a few minutes, the metal spoon feels much hotter than the wooden spoon when touched outside the cup.
Which statement best explains this observation?
A. Metal produces heat when placed in hot water, while wood absorbs all heat energy.
B. Heat moves faster through metal than through wood, allowing thermal energy to transfer more quickly.
C. Wood reflects thermal energy back into the water, while metal destroys heat energy.
D. Metal stores thermal energy inside itself, while wood prevents any heat from entering.
B. Heat moves faster through metal than through wood, allowing thermal energy to transfer more quickly.
A student uses a lamp and a globe to model Earth. The student notices that as the globe slowly spins, different cities move from the lighted side to the dark side and then back again.
Which statement best explains what causes this pattern of day and night?
A. Earth rotates on its axis, causing locations to move in and out of sunlight as it spins.
B. Earth moves closer and farther from the Sun during the day, changing which areas receive light.
C. The Sun rotates around Earth once every 24 hours, making different areas light and dark.
D. Earth’s tilt causes one half of the planet to stay in sunlight while the other half stays dark.
A. Earth rotates on its axis, causing locations to move in and out of sunlight as it spins.
In a forest ecosystem, grass is eaten by rabbits and insects. Rabbits are eaten by foxes, and insects are eaten by frogs. Frogs are then eaten by snakes, and snakes are eaten by hawks.
Which statement best explains what would most likely happen if the rabbit population suddenly decreased?
A. The fox population would increase because they would have more food options.
B. The grass population would increase because fewer rabbits would be eating it.
C. The insect population would decrease because rabbits compete with insects for food.
D. The snake population would increase because more frogs would be available to eat.
B. The grass population would increase because fewer rabbits would be eating it.