Vermont Comprehensive Assessment Program Science — Grade 8

A student constructs a 3D ball-and-stick model of a carbon dioxide (CO2) molecule. Which configuration correctly represents this molecule?

• AOne carbon atom in the center double-bonded to two oxygen atoms in a straight line
• BTwo carbon atoms bonded to one central oxygen atom in a triangular shape
• CThree carbon atoms bonded sequentially in a bent formation
• DOne oxygen atom in the center with two carbon atoms attached at right angles

When solid ice melts into liquid water, what happens to the motion and thermal energy of the water molecules?

• AThermal energy increases, allowing molecules to overcome rigid positions and slide past o…
• BThermal energy decreases, causing molecules to lock into a rigid crystal lattice
• CThermal energy remains zero while molecules move infinitely far apart
• DThermal energy increases, causing molecules to break down into separate hydrogen and oxyg…

A heavy wooden box sits motionless on a classroom floor. Two students push on opposite sides of the box with equal force (50 N to the right and 50 N to the left). What is the net force acting on the box, and how does it move?

• AThe net force is 0 N, and the box remains motionless because the forces are balanced
• BThe net force is 100 N to the right, causing the box to accelerate rightward
• CThe net force is 50 N upward, causing the box to lift off the floor
• DThe net force is 100 N to the left, causing the box to accelerate leftward

A student standing on a skateboard pushes backward against a brick wall. What happens according to Newton's Third Law of Motion?

• AThe wall exerts an equal and opposite forward force on the student, rolling the student a…
• BThe wall absorbs the push entirely, leaving both the student and skateboard stationary
• CThe student exerts a force on the wall, but the wall exerts no force back on the student
• DThe skateboard moves forward while the student is pushed backward into the wall

Two identical bicycles are traveling down a flat path. Bicycle A moves at 5 m/s, while Bicycle B moves at 10 m/s. How does the kinetic energy of Bicycle B compare to Bicycle A?

• ABicycle B has four times the kinetic energy of Bicycle A because kinetic energy depends o…
• BBicycle B has half the kinetic energy of Bicycle A because speed reduces energy
• CBicycle B has twice the kinetic energy of Bicycle A because speed is doubled
• DBicycle B has equal kinetic energy to Bicycle A because their masses are identical

A student holds a 1 kg basketball at a height of 1 meter above the floor, and then lifts it to a height of 2 meters. How does the gravitational potential energy of the basketball change?

• AIt doubles because gravitational potential energy is directly proportional to height
• BIt drops to zero because potential energy converts into mass
• CIt decreases by half because greater height reduces gravity
• DIt remains unchanged because the mass of the ball stays constant

A scientist measures two ocean waves. Wave X has an amplitude of 0.5 meters, while Wave Y has an amplitude of 2.0 meters. Which statement correctly compares the energy carried by the two waves?

• AWave Y carries significantly more energy than Wave X because wave energy increases with a…
• BWave X carries more energy because smaller waves travel faster
• CBoth waves carry the same energy because wave energy depends only on water temperature
• DWave Y carries less energy because large waves lose energy instantly

When sunlight shines on a smooth glass mirror, most of the light bounces off the surface at the same angle it hit. Which wave behavior does this demonstrate?

• AReflection
• BRefraction
• CAbsorption
• DDiffraction

A solid block has a mass of 120 grams and a volume of 60 cubic centimeters (cm³). What is the density of the block, and will it float or sink in pure water (density = 1.0 g/cm³)?

• ADensity = 2.0 g/cm³; it will sink because its density is greater than water
• BDensity = 0.5 g/cm³; it will float because its density is less than water
• CDensity = 180 g/cm³; it will sink because mass and volume add together
• DDensity = 1.0 g/cm³; it will remain suspended anywhere in water

A student mixes baking soda powder into a cup of vinegar. Bubbles immediately form, the liquid fizzes, and the temperature of the cup drops. What type of change occurred?

• AA chemical reaction, because a new gas substance was produced
• BA physical change, because the liquid simply changed shape
• CA nuclear change, because atoms were converted into different elements
• DNo change, because mixing two liquids always forms a mechanical mixture

Which organelle is found in plant cells but is absent in animal cells, providing structural support and rigidity?

• ACell wall
• BCell membrane
• CNucleus
• DMitochondria

What is the primary function of the cell membrane in both plant and animal cells?

• AControlling which substances enter and leave the cell
• BSynthesizing glucose molecules from sunlight
• CStoring genetic instructions in chromosomes
• DBreaking down waste products using digestive enzymes

What are the essential starting materials (reactants) required for green plants to carry out photosynthesis?

• ACarbon dioxide, water, and sunlight energy
• BGlucose, oxygen, and soil minerals
• CNitrogen gas, oxygen, and thermal energy
• DWater, glucose, and carbon dioxide

Fungi and bacteria feed on dead forest trees and fallen leaves. What ecological role do these organisms play in an ecosystem?

• ADecomposers that break down organic matter and recycle nutrients into the soil
• BPrimary producers that convert solar radiation into chemical energy
• CApex predators that control herbivore populations
• DSecondary consumers that hunt live plant material

In a Vermont meadow ecosystem food chain (Grass -> Grasshopper -> Garter Snake -> Red-tailed Hawk), which organism represents the primary producer?

• AGrass
• BGrasshopper
• CGarter Snake
• DRed-tailed Hawk

Where are genes located inside a eukaryotic plant or animal cell, and what is their main function?

• AOn chromosomes inside the nucleus; they provide instructions for building proteins
• BIn the cell membrane; they absorb water from outside the cell
• CInside the vacuole; they store excess sugars for winter energy
• DFloating freely in the cytoplasm; they pump waste out of the cell

How does the genetic makeup of offspring produced by asexual reproduction compare to offspring produced by sexual reproduction?

• AAsexual offspring are genetically identical to one parent, while sexual offspring inherit…
• BAsexual offspring inherit genes from two parents, while sexual offspring are clones of on…
• CBoth asexual and sexual offspring are 100% identical to both parents
• DSexual offspring have no DNA, while asexual offspring have double the DNA

Cactus plants have thick waxy stems and needle-like spines instead of broad leaves. How do these traits help the cactus survive in arid desert environments?

• AThey reduce water loss and protect the plant from herbivores
• BThey attract pollinators during cold night temperatures
• CThey absorb high amounts of snowfall during desert winters
• DThey allow the plant to swim in desert floods

Scientists examine rock layers and find fossils of simple single-celled organisms in deep, ancient layers, and complex multi-celled organisms in younger, higher layers. What does this evidence demonstrate?

• ALife on Earth has changed and grown more complex over geological time
• BOrganisms in ancient times were larger than modern organisms
• CRock layers flip upside down every few thousand years
• DAll modern animal species existed at the exact same time Earth formed

In pea plants, the allele for tall height (T) is dominant over the allele for short height (t). If two heterozygous pea plants (Tt x Tt) are crossed, what percentage of the offspring are expected to be tall?

• A75%
• B25%
• C50%
• D100%

Why do locations on Earth experience a repeating 24-hour cycle of day and night?

• AEarth rotates on its axis once every 24 hours
• BThe Sun orbits around the Earth once every 24 hours
• CThe Moon blocks the Sun's light every night
• DEarth moves closer to and further from the Sun each day

What is the primary cause of seasonal temperature changes (summer, fall, winter, spring) in Vermont?

• AThe tilt of Earth's axis as it orbits around the Sun
• BChanges in the distance between Earth and the Sun throughout the year
• CVarying energy output emitted by the Sun on a monthly schedule
• DOcean tides pulling warm atmospheric air away from the poles

Which fundamental force keeps planets, dwarf planets, and asteroids orbiting around the Sun in our solar system?

• AGravity
• BMagnetism
• CFriction
• DElectrostatic force

Water vapor in the atmosphere cools down and changes into liquid water droplets to form clouds. What step of the water cycle is this?

• ACondensation
• BEvaporation
• CTranspiration
• DInfiltration

A geologist collects a rock sample near an ancient volcano. The rock formed when molten lava cooled and solidified on Earth's surface. What classification does this rock belong to?

• AIgneous rock
• BSedimentary rock
• CMetamorphic rock
• DFossilized rock

When two continental tectonic plates collide head-on over millions of years, what landform is most likely created at the convergent boundary?

• AMountain range
• BMid-ocean ridge
• CRift valley
• DSubmarine trench

Which statement correctly distinguishes between weathering and erosion?

• AWeathering breaks down rocks into smaller pieces, while erosion transports those rock pie…
• BWeathering moves rocks using wind, while erosion freezes rocks into ice
• CWeathering builds new mountains, while erosion causes volcanic eruptions
• DWeathering only occurs in oceans, while erosion only occurs on land

What is the primary driving force behind global atmospheric wind patterns on Earth?

• AUneven solar heating of Earth's surface creating temperature and air pressure differences
• BGravitational pull of the Moon on surface clouds
• CHeat released from deep ocean hydrothermal vents
• DFriction created by aircraft flying through the atmosphere

Which set of energy resources consists entirely of renewable energy sources?

• ASolar, wind, and hydroelectric power
• BCoal, natural gas, and solar power
• CPetroleum, wind, and nuclear uranium
• DNatural gas, geothermal, and coal

How do greenhouse gases in Earth's atmosphere (such as carbon dioxide and water vapor) help regulate surface temperatures?

• AThey absorb thermal infrared radiation emitted by Earth and re-radiate heat back toward t…
• BThey reflect 100% of incoming sunlight before it reaches Earth's surface
• CThey generate internal heat through chemical nuclear fusion in clouds
• DThey trap cold polar air and prevent it from moving toward the equator

A student seals a piece of steel wool inside a flask containing oxygen gas. The total mass of the sealed flask and contents is 250.0 grams. After several days, the steel wool rusts completely. What is the final total mass of the sealed flask?

• AExactly 250.0 grams, because mass is conserved in a closed system
• B240.0 grams, because chemical reactions destroy mass
• C260.0 grams, because rust adds new matter from nowhere
• D0.0 grams, because solid steel converted entirely into energy

A student places a wooden spoon, a plastic spoon, and a stainless steel spoon into a pot of hot water (80°C). After 3 minutes, which spoon handle will feel the hottest to touch, and why?

• AThe stainless steel spoon, because metals are good thermal conductors
• BThe wooden spoon, because wood generates internal heat when wet
• CThe plastic spoon, because plastic traps heat and amplifies temperature
• DAll three spoons will feel identical because heat moves at equal rates in all solids

How does the gravitational force between two asteroids change if the distance between them is doubled?

• AThe gravitational force decreases to one-fourth (1/4) of its original strength
• BThe gravitational force doubles in strength
• CThe gravitational force drops to zero instantly
• DThe gravitational force quadruples (increases by 4x)

A distance vs. time graph shows a straight line sloping upward from left to right. What does this graph indicate about the motion of the object?

• AThe object is moving at a constant speed
• BThe object is accelerating at an increasing rate
• CThe object is completely stationary
• DThe object is moving backward toward the starting line

A student moves a bar magnet toward a pile of iron paperclips. Which investigation procedure tests how magnetic field strength varies with distance?

• AMeasuring the maximum distance at which paperclips begin moving toward the magnet
• BHeating the magnet with a flame to see if paperclips melt
• CCounting paperclips while painting the magnet different colors
• DWeighing paperclips on a digital scale before touching the magnet

Why can sunlight travel through the vacuum of outer space to reach Earth, whereas the sound of a solar flare explosion cannot be heard on Earth?

• ALight is an electromagnetic wave that requires no material medium, whereas sound is a mec…
• BSound waves travel too slowly to cover space distances, whereas light moves instantly
• CLight waves carry matter across space, whereas sound waves carry zero energy
• DSpace contains cold gases that absorb sound but amplify sunlight

Modern communication technologies use digital signals (binary 0s and 1s) rather than continuous analog signals to transmit information over long distances. What is a primary technical advantage of digital signals?

• ADigital signals can be easily filtered to remove noise and distortion during transmission
• BDigital signals do not require any energy or electricity to transmit
• CDigital signals travel faster than the speed of light in fiber optics
• DDigital signals can only be received by wooden antennas

A student dissolves ammonium nitrate crystals in a beaker of room-temperature water. The temperature of the solution drops from 22°C to 14°C. What type of reaction occurred, and what happened to thermal energy?

• AAn endothermic process; energy was absorbed from the surrounding water into the chemical…
• BAn exothermic process; energy was released from the chemical system into the water
• CA nuclear reaction; mass was converted into cold light
• DA physical destruction of energy; thermal energy was destroyed permanently

A roller coaster car rests at the top of a 50-meter hill before rolling down to the bottom. Ignoring friction, how do the potential energy (PE) and kinetic energy (KE) change as the car descends?

• APE decreases while KE increases, keeping total mechanical energy constant
• BBoth PE and KE increase simultaneously as speed increases
• CPE increases while KE decreases to zero at the bottom
• DPE converts into mass while KE disappears

A 10 kg sled is pulled to the right across snow with a force of 30 N. At the same time, friction exerts a force of 10 N to the left. What is the net force acting on the sled?

• A20 N to the right
• B40 N to the right
• C300 N upward
• D10 N to the left

Plastic water bottles are synthetic materials made from petroleum (crude oil). Which statement describes how synthetic materials relate to natural resources?

• ASynthetic materials are engineered by chemically processing natural resources
• BSynthetic materials form naturally underground without human intervention
• CSynthetic materials do not use any matter or energy from Earth
• DSynthetic materials can only be created from plant leaves

A wave generator creates waves in a water tank at constant wave speed. If the frequency of the wave generator is doubled, what happens to the wavelength of the water waves?

• AThe wavelength is cut in half
• BThe wavelength doubles
• CThe wavelength quadruples
• DThe wavelength remains unchanged

Which statement correctly describes particle arrangement and movement in a gas compared to a liquid?

• AGas particles are far apart and move rapidly in all directions, whereas liquid particles…
• BGas particles are locked in fixed positions, whereas liquid particles move freely
• CGas particles are more tightly packed than liquid particles
• DGas particles have zero kinetic energy, whereas liquid particles vibrate in place

A student wraps insulated copper wire around an iron nail and connects the wire ends to a D-cell battery to make an electromagnet. Which modification will increase the strength of the magnetic field?

• AIncreasing the number of wire coils wrapped around the nail
• BRemoving the iron nail from inside the coils
• CUsing a smaller battery with lower voltage
• DReplacing the copper wire with plastic string

Equal masses (100 g) of water, aluminum, copper, and sand receive the exact same amount of thermal heat energy. Water has the highest specific heat capacity. Which substance will show the SMALLEST increase in temperature?

• AWater
• BAluminum
• CCopper
• DSand

A student investigates how surface area affects the rate of a chemical reaction. Two identical antacid tablets are placed into separate beakers containing equal volumes of water at 20°C. Tablet A is left whole, while Tablet B is crushed into fine powder. What will the student observe?

• ATablet B will dissolve and react faster because crushing increases the surface area expos…
• BTablet A will react faster because whole tablets contain more total mass
• CBoth tablets will react at identical rates because chemical composition is unchanged
• DNeither tablet will react because temperature is below boiling point

A pencil placed in a clear glass of water appears bent or broken at the water line when viewed from the side. What wave phenomenon causes this optical illusion?

• ARefraction, because light changes speed and bends as it passes from water into air
• BReflection, because light bounces off the wooden pencil back into the water
• CAbsorption, because water destroys light waves passing through it
• DDiffraction, because light waves spread out around the pencil edges