West Virginia General Summative Assessment Science — Grade 8

Which subatomic particle carries a negative electrical charge and orbits the nucleus of an atom?

• AProton
• BNeutron
• CElectron
• DPositron

A student observes a substance whose particles are tightly packed in fixed positions and vibrate in place. Which state of matter is the student observing?

• ASolid
• BLiquid
• CGas
• DPlasma

Which event is an example of a chemical change rather than a physical change?

• AIce melting into liquid water
• BIron rusting when exposed to oxygen and moisture
• CSugar dissolving in a glass of warm water
• DCrushing an aluminum soda can

Consider the following chemical equation for photosynthesis: 6 CO2 + 6 H2O -> C6H12O6 + 6 O2. Which substances represent the reactants?

• AC6H12O6 and O2
• BCO2 and H2O
• CCO2 and O2
• DH2O and C6H12O6

When a car stops suddenly, a passenger sways forward against their seatbelt. Which physical law explains this phenomenon?

• ANewton's First Law of Motion (Law of Inertia)
• BNewton's Second Law of Motion (F = ma)
• CNewton's Third Law of Motion (Action-Reaction)
• DLaw of Conservation of Energy

A runner completes a 400-meter track event in 50 seconds. What is the average speed of the runner?

• A4 m/s
• B8 m/s
• C20 m/s
• D200 m/s

At which point on a roller coaster track does a coaster car possess the maximum gravitational potential energy?

• AAt the lowest point of the track
• BAt the top of the highest hill
• CHalfway down the main drop
• DAt the end of the ride when stopped

Kinetic energy is best described as the energy an object possesses due to its:

• APosition above Earth's surface
• BChemical composition
• CMotion
• DTemperature relative to surroundings

In a transverse wave, what is the term for the distance from one crest to the next consecutive crest?

• AAmplitude
• BFrequency
• CWavelength
• DTrough

Why can sound waves travel through air, water, and steel, but CANNOT travel through the vacuum of outer space?

• ASound waves travel too fast for space
• BSound waves require matter (a medium) to vibrate and transmit energy
• CSpace temperature is too cold for sound waves to exist
• DGravity in space absorbs sound wave energy

When a beam of light strikes a flat glass mirror and bounces off at the exact same angle, which wave behavior is occurring?

• ARefraction
• BDiffraction
• CReflection
• DAbsorption

A student mixes 50 grams of vinegar and 10 grams of baking soda in a sealed flask on a digital balance. A vigorous bubbling reaction occurs. What will the total mass shown on the balance be after the reaction finishes?

• ALess than 60 grams because gas bubbles escaped
• BExactly 60 grams because mass is conserved in a closed system
• CMore than 60 grams because new carbon dioxide gas was created
• D0 grams because liquid turned into gas

Students measure the temperature of two chemical reactions over 5 minutes: • Reaction A: Initial Temp = 22°C, Final Temp = 34°C • Reaction B: Initial Temp = 22°C, Final Temp = 14°C Which classification correctly identifies Reactions A and B?

• AReaction A is endothermic; Reaction B is exothermic
• BReaction A is exothermic; Reaction B is endothermic
• CBoth reactions are exothermic
• DBoth reactions are physical changes

A solid block has a mass of 120 grams and a volume of 40 cubic centimeters. Pure water has a density of 1.0 g/cm3. Will the block sink or float when placed in water?

• AFloat, because its density is 0.33 g/cm3
• BFloat, because its density is 3.0 g/cm3
• CSink, because its density is 3.0 g/cm3
• DSink, because its volume is larger than its mass

Plastics are synthetic materials derived from petroleum hydrocarbons. What is a major societal and environmental impact of replacing natural materials with synthetic plastics?

• ASynthetic plastics decompose faster in nature than paper or cotton
• BPlastics are durable and low-cost, but resist natural decomposition leading to long-term…
• CPetroleum used for plastics is an infinite renewable resource
• DPlastics require no chemical processing during manufacturing

Two forces act on a wooden crate resting on a smooth floor: Force 1 pulls left with 15 N, and Force 2 pulls right with 35 N. What is the magnitude and direction of the net force acting on the crate?

• A50 N to the right
• B20 N to the right
• C20 N to the left
• D50 N to the left

Using Newton's Second Law (F = ma), if a constant net force of 60 N is applied to two different carts, Cart A (mass = 10 kg) and Cart B (mass = 20 kg), how will their accelerations compare?

• ACart A will accelerate at 6 m/s2, which is twice the acceleration of Cart B (3 m/s2)
• BCart B will accelerate at 12 m/s2, which is twice the acceleration of Cart A
• CBoth carts will accelerate at the same rate of 60 m/s2
• DCart A will remain stationary while Cart B accelerates

A space rocket launches upward as hot exhaust gases are pushed rapidly out of its engines downward. Which statement accurately describes the action-reaction force pair?

• AThe rocket engine pushes exhaust gases downward (action), and gravity pulls the rocket do…
• BThe rocket engine pushes exhaust gases downward (action), and the exhaust gases push the…
• CAir pressure pushes the rocket upward (action), and rocket engines push air downward (rea…
• DThe ground pushes the rocket upward (action), and rocket mass pushes the ground downward…

Which two variables determine the strength of the gravitational force between two objects in the universe?

• AMass of the objects and distance between their centers
• BVolume of the objects and their surface temperature
• CElectrical charge of the objects and speed of rotation
• DDensity of the objects and atmospheric pressure

A student builds an electromagnet by wrapping copper wire around an iron nail connected to a battery. How can the student increase the magnetic field strength of the electromagnet?

• AIncrease the number of wire coils around the nail and increase electrical current
• BRemove the iron nail core and use plastic instead
• CDecrease the current by using a weaker battery
• DUncoil the wire so it forms a straight line

A pendulum swings back and forth. At the lowest point of its swing (equilibrium position), how are its potential and kinetic energy distributed?

• APotential energy is at its maximum and kinetic energy is zero
• BKinetic energy is at its maximum and potential energy is at its minimum
• CBoth potential and kinetic energy are zero
• DPotential energy and kinetic energy are both at maximum simultaneously

Solar radiation warms the Earth's surface, which then heats the air directly above it by contact. As this warm air expands and rises, cooler air sinks to replace it. Which heat transfer process is created by this rising and falling air loop?

• AConduction
• BConvection
• CRadiation
• DInsulation

If the speed of a wave remains constant in a medium, what happens to the wavelength if the frequency of the wave is doubled?

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

Why are digital signals (binary 0s and 1s) widely preferred over continuous analog signals for modern data storage and wireless communication?

• ADigital signals travel faster than the speed of light
• BDigital signals can be filtered to remove signal noise and interference without losing da…
• CAnalog signals cannot carry audio or video content
• DDigital signals require larger physical copper cables

Which portion of the electromagnetic spectrum has higher frequency and carries more energy than visible light?

• ARadio waves
• BMicrowaves
• CInfrared light
• DUltraviolet light

When a straight straw is placed into a clear cup of water, the straw appears bent or broken at the water line. Which wave interaction causes this optical illusion?

• ARefraction, because light changes speed as it travels from air into water
• BReflection, because light bounces off the surface of the plastic straw
• CDiffraction, because light waves bend around the edges of the cup
• DAbsorption, because water absorbs red wavelengths of light

Students perform an experiment combining solution X and solution Y. Which observation provides definitive evidence that a chemical reaction occurred?

• ASolution X mixed uniformly with solution Y
• BAn insoluble solid (precipitate) formed and settled at the bottom of the beaker
• CThe total volume equaled the sum of both individual solutions
• DThe liquid became warmer when heated on a hot plate

A toy car rolls down two identical inclined ramps: Ramp 1 is covered in smooth plastic, while Ramp 2 is covered in coarse sandpaper. Why does the car travel faster and further on Ramp 1?

• ARamp 1 has higher gravitational pull than Ramp 2
• BSandpaper on Ramp 2 creates greater frictional force, converting kinetic energy into ther…
• CSmooth plastic increases the mass of the toy car
• DRamp 2 eliminates friction entirely

An open beaker containing 100 g of reactant solution is mixed with 15 g of solid reactant. The reaction produces carbon dioxide gas bubbles. After 10 minutes, the open beaker mass measures 111 g. How much gas escaped into the atmosphere?

• A4 g
• B15 g
• C100 g
• D115 g

The kinetic energy equation is KE = 0.5 * m * v^2. If a truck's mass is doubled while its velocity remains constant, its kinetic energy doubles. However, if the truck's velocity is doubled while mass remains constant, by what factor does its kinetic energy increase?

• A2 times
• B4 times
• C8 times
• D16 times

A 5 kg sled is pulled across ice with an applied horizontal force of 25 N. The frictional force opposing motion is 5 N. What is the net acceleration of the sled?

• A4 m/s2
• B5 m/s2
• C6 m/s2
• D20 m/s2

An investigation tests light transmission through three materials: • Material X transmits 95% of incoming light rays • Material Y reflects 90% of incoming light rays • Material Z absorbs 92% of incoming light rays Which material should be selected to construct energy-efficient dark curtains that prevent solar heating of a room?

• AMaterial X because it lets light pass through without heat buildup
• BMaterial Y because reflecting light prevents thermal energy absorption inside the room
• CMaterial Z because absorbing light converts light into useful room cooling
• DA equal mix of Material X and Material Z

A life-cycle assessment compares natural cotton grocery bags with synthetic polyethylene plastic bags. Cotton bags require large land areas and high water usage to grow, but biodegrade in months. Polyethylene bags require low water during production, but persist in oceans for centuries. What is a key scientific conclusion from this data?

• ASynthetic materials have zero negative environmental impacts across their life cycle
• BNatural materials are always superior to synthetic materials in every stage of resource e…
• CEvaluating material sustainability requires analyzing both production resource costs and…
• DPlastics biodegrade faster when submerged in ocean saltwater

A student tests how coil turns affect electromagnet strength by measuring paperclips picked up: • 10 turns: 3 paperclips • 20 turns: 7 paperclips • 30 turns: 12 paperclips • 40 turns: 16 paperclips Predict how many paperclips a 50-turn coil will pick up based on this trend.

• A3 paperclips
• B8 paperclips
• C20 to 22 paperclips
• D50 paperclips

Equal masses of 80°C hot water and 20°C cold water are mixed together in an insulated container. Assuming no heat is lost to the container or surroundings, what is the final equilibrium temperature of the mixture?

• A30°C
• B50°C
• C60°C
• D100°C

Which cell organelle regulates what enters and exits the cell, maintaining internal homeostasis?

• ACell membrane
• BCell wall
• CVacuole
• DChloroplast

Which organelle is found in plant cells but NOT in animal cells and captures sunlight to produce glucose?

• AMitochondrion
• BRibosome
• CChloroplast
• DNucleus

Why are mitochondria often referred to as the 'powerhouses' of eukaryotic cells?

• AThey store liquid water for cell turgor pressure
• BThey carry out cellular respiration to convert food energy into usable ATP energy
• CThey package proteins into transport vesicles
• DThey replicate DNA during cell division

Which sequence correctly orders the levels of biological organization in multicellular organisms from simplest to most complex?

• AOrganism -> Organ System -> Organ -> Tissue -> Cell
• BCell -> Tissue -> Organ -> Organ System -> Organism
• CTissue -> Cell -> Organ -> Organism -> Organ System
• DCell -> Organ -> Tissue -> Organ System -> Organism

What are the primary outputs (products) generated during plant photosynthesis?

• ACarbon dioxide and water
• BGlucose and oxygen
• CSunlight and chlorophyll
• DNitrogen and carbon dioxide

In a woodland food web, which organism functions as a primary producer?

• ARed fox
• BWhite-tailed deer
• COak tree
• DEarthworm

What essential ecological role do fungi and bacteria play within a natural forest ecosystem?

• AThey harvest sunlight to replenish oxygen gas in the atmosphere
• BThey break down dead plant and animal remains, recycling nutrients back to the soil
• CThey hunt primary consumers to control herbivore populations
• DThey act as top predators in soil food webs

Where is the genetic instruction manual (DNA) stored within a eukaryotic cell?

• ACytoplasm
• BNucleus
• CRibosome
• DCell wall

A pea plant has the genetic gene combination 'Tt' for plant height. Which term describes 'Tt' and which term describes the resulting tall appearance?

• A'Tt' is the phenotype; tall appearance is the genotype
• B'Tt' is the genotype; tall appearance is the phenotype
• CBoth 'Tt' and tall appearance are phenotypes
• DBoth 'Tt' and tall appearance are genotypes

Which core principle best explains why trait frequencies change in a population over successive generations during natural selection?

• AOrganisms decide to change their DNA to fit new environments
• BIndividuals with traits better adapted to their environment survive and reproduce more su…
• CAll offspring in a species inherit identical genetic traits
• DEnvironments cause beneficial mutations to occur whenever needed

How do scientists use fossils preserved in rock layers to reconstruct the history of life on Earth?

• AFossils show that ancient species were identical to modern living animals
• BOlder rock layers generally contain fossils of simpler organisms, showing evolutionary ch…
• CFossils prove that Earth is only a few thousand years old
• DFossils reveal how modern animals learn behavioral skills

A student views an unidentified tissue sample under a microscope and notes rectangular cells containing green oval structures and rigid outer borders. What type of cells are these?

• AAnimal skin cells
• BPlant leaf cells
• CHuman red blood cells
• DFungal mushroom cells