Wisconsin Forward Exam Science — Grade 8

A student measures the mass of a sealed flask containing 10 g of baking soda and 20 g of vinegar. After mixing the substances inside the sealed flask, a gas forms and bubbles appear. What is the total mass of the flask and its contents after the reaction?

• AExactly 30 g plus the mass of the flask
• BLess than 30 g because gas was produced
• CMore than 30 g because bubbles add weight
• D0 g because a chemical change destroyed matter

Which subatomic particles are located inside the nucleus of an atom?

• AProtons and neutrons
• BProtons and electrons
• CElectrons and neutrons
• DElectrons only

A wooden block is pushed across a table and then released. It slides a short distance and comes to a stop. Which force causes the block to slow down and stop?

• AFriction between the block and table
• BGravity pulling the block downward
• CAir resistance acting upward
• DThe initial push force continuing to act

Which state of matter has a definite volume but no definite shape, conforming to the shape of its container?

• ALiquid
• BSolid
• CGas
• DPlasma

A skateboarder starts at the top of a ramp, rolls down, and speeds up. How does her kinetic energy change as she moves down the ramp?

• AKinetic energy increases as potential energy decreases
• BKinetic energy decreases as potential energy increases
• CKinetic energy remains constant throughout the motion
• DKinetic energy decreases to zero at the bottom

Which of the following is a clear indicator that a chemical change has taken place when two solutions are mixed?

• AFormation of a precipitate (solid formation)
• BLiquid changing shape when poured into a glass
• CSugar dissolving completely in warm water
• DIce melting into liquid water

Light passing from air into water bends at the boundary. What is this phenomenon called?

• ARefraction
• BReflection
• CAbsorption
• DDiffraction

Which type of heat transfer occurs when hot water rises and cooler water sinks in a heated pot on a stove?

• AConvection
• BConduction
• CRadiation
• DInsulation

Which simple wave property corresponds to the height of a wave crest from its resting position?

• AAmplitude
• BWavelength
• CFrequency
• DWave speed

Two bar magnets are pushed together so that their North poles face each other. What force behavior occurs between them?

• AThey repel each other
• BThey attract each other
• CNo magnetic force occurs
• DThey combine into one larger pole

Which organelle is often called the 'powerhouse of the cell' because it produces usable energy (ATP) through cellular respiration?

• AMitochondrion
• BNucleus
• CChloroplast
• DRibosome

Plant cells have several structures that animal cells lack. Which structure provides rigid support and shape to plant cells?

• ACell wall
• BCell membrane
• CCytoplasm
• DMitochondria

What are the primary reactants needed by plants to carry out photosynthesis?

• ACarbon dioxide and water
• BOxygen and glucose
• CNitrogen and carbon dioxide
• DGlucose and water

In a forest food web, which organisms are classified as producers?

• AOak trees and ferns
• BFungi and bacteria
• CDeer and rabbits
• DWolves and hawks

Which biological term describes a trait that helps an organism survive and reproduce in its specific environment?

• AAdaptation
• BMutation
• CExtinction
• DDominance

In humans, brown eyes ($B$) are dominant over blue eyes ($b$). If an individual has a genotype of $Bb$, what is their phenotype?

• ABrown eyes
• BBlue eyes
• CGreen eyes
• DOne blue eye and one brown eye

Which organ system is responsible for transporting oxygen, nutrients, and waste products throughout the human body?

• ACirculatory system
• BRespiratory system
• CDigestive system
• DNervous system

A bee gathers nectar from flowers for food, while pollinating the flowers in the process. What symbiotic relationship is this?

• AMutualism
• BParasitism
• CCommensalism
• DPredation

Where is the genetic code stored inside a eukaryotic cell?

• AOn DNA molecules inside the nucleus
• BInside the cell wall cellulose fibers
• CDissolved in water in the cytoplasm
• DWithin lipid molecules in the cell membrane

Which process produces offspring that are genetically identical to a single parent organism?

• AAsexual reproduction
• BSexual reproduction
• CCross-pollination
• DFertilization

What causes the apparent changing shapes of the Moon (lunar phases) as observed from Earth?

• AThe changing angle of sunlight reflecting off the Moon as it orbits Earth
• BEarth's shadow blocking sunlight from reaching the Moon each night
• CClouds in Earth's atmosphere covering parts of the lunar surface
• DThe Moon growing larger and smaller as distance changes

Which layer of the Earth is broken into large tectonic plates that move across the softer asthenosphere below?

• ALithosphere
• BOuter core
• CInner core
• DAtmosphere

What primary force holds planets in their orbits around the Sun?

• AGravitational force
• BMagnetic force
• CFrictional force
• DElectrostatic force

Which process in the water cycle involves water vapor cooling and changing into liquid water droplets to form clouds?

• ACondensation
• BEvaporation
• CTranspiration
• DPrecipitation

Which category of rock forms when molten magma or lava cools and solidifies?

• AIgneous rock
• BSedimentary rock
• CMetamorphic rock
• DFossiliferous rock

Why does Wisconsin experience warmer temperatures in July than in January?

• AEarth's Northern Hemisphere is tilted toward the Sun in July, receiving more direct sunli…
• BEarth is significantly closer to the Sun in July than in January
• CThe Sun produces more nuclear energy during summer months
• DOcean currents stop flowing in winter months

Fossils of marine ocean sea shells are discovered near the top of a mountain range. What does this evidence indicate about the area's geological past?

• AThe mountain area was once submerged under an ancient ocean floor
• BOcean animals climbed the mountain during ancient storms
• CThe fossils fell onto the mountain from space meteorites
• DVolcanoes produced artificial shells during mountain eruptions

What is the first step engineers take when using the engineering design process to solve a problem?

• ADefine the problem, criteria, and constraints
• BBuild a full-scale final model immediately
• CSell the product to consumers
• DDisregard material safety regulations

In engineering design, what is a limitation or restriction placed on a project called (e.g., budget limits, weight limits)?

• AConstraint
• BCriterion
• CPrototype
• DHypothesis

Why do engineers build and test preliminary physical models (prototypes) before mass-producing a new design?

• ATo identify flaws and optimize performance before final manufacturing
• BTo guarantee that no testing will be needed later
• CTo increase manufacturing costs as much as possible
• DTo replace all computer simulation modeling completely

A scientist investigates the solubility of potassium nitrate ($KNO_3$) in water across different water temperatures. The results are recorded in the data table below: Water Temp (°C) | Solubility (g per 100 g $H_2O$) 10 | 21 30 | 46 50 | 85 70 | 140 Based on these experimental data, what is the best prediction for the solubility of potassium nitrate at 40°C?

• AApproximately 65 g per 100 g $H_2O$
• BApproximately 20 g per 100 g $H_2O$
• CExactly 140 g per 100 g $H_2O$
• DOver 200 g per 100 g $H_2O$

A student dissolves 15 g of salt into 100 g of water, creating a salt solution. Which statement correctly describes this mixture?

• AThe total mass of the solution is 115 g, representing a physical change
• BThe total mass is 100 g because salt disappears chemically
• CThe solution weighs 85 g because salt reduces liquid volume
• DA new element was synthesized through chemical fusion

Two identical toy cars are pushed with different forces on a frictionless floor. Car A is pushed with a net force of 10 N, while Car B is pushed with a net force of 5 N. According to Newton's Second Law ($F = ma$), how will Car A's acceleration compare to Car B's acceleration?

• ACar A will accelerate at twice the rate of Car B
• BCar B will accelerate at twice the rate of Car A
• CBoth cars will accelerate at identical rates
• DCar A will stop moving while Car B accelerates

A balloon is rubbed against a wool sweater, giving the balloon a negative static electric charge. When brought near neutral wall paper, the balloon sticks to the wall. Why does this occur?

• AThe negative balloon repels electrons in the wall, inducing a positive surface charge tha…
• BThe balloon melts the surface layer of the wall paint creating adhesive glue
• CGravity pushes the balloon horizontally against the wall
• DMagnetic poles inside wool align with magnetic poles in drywall

The diagram below shows three points on a roller coaster track: - Point X: Top of the highest hill (start from rest) - Point Y: Bottom of the first dip - Point Z: Top of a second, smaller hill At which point does the roller coaster car possess the maximum kinetic energy?

• APoint Y
• BPoint X
• CPoint Z
• DKinetic energy is identical at all three points

A student places a hot metal spoon (80°C) into a cup of cold water (10°C). Which statement describes the direction and mechanism of thermal energy transfer?

• AThermal energy flows from the hot spoon to the cold water by conduction until thermal equ…
• BCold energy flows from the water into the spoon by radiation
• CThermal energy flows back and forth indefinitely without changing temperatures
• DHeat flows from the water to the spoon because water has higher mass

A sound wave travels through air, water, and steel. In which medium will the sound wave travel fastest, and why?

• ASteel, because tightly packed particles transfer vibrational energy more rapidly
• BAir, because low density allows sound waves to move freely
• CWater, because liquids compress easily under wave pressure
• DSound travels at equal speed through all states of matter

The diagram below represents two transverse waves generated over 1 second: - Wave 1: 4 full wave cycles - Wave 2: 8 full wave cycles How do the frequency and energy of Wave 2 compare to Wave 1?

• AWave 2 has higher frequency and carries higher energy than Wave 1
• BWave 2 has lower frequency and lower energy than Wave 1
• CWave 2 has higher frequency but lower energy than Wave 1
• DWave 2 has lower frequency and higher energy than Wave 1

A student tests four different liquids with red and blue litmus paper to determine pH characteristics. The results are recorded below: - Liquid A: Red stays red; Blue turns red - Liquid B: Red turns blue; Blue stays blue - Liquid C: Red stays red; Blue stays blue - Liquid D: Red turns blue; Blue stays blue Which liquid is acidic?

• ALiquid A
• BLiquid B
• CLiquid C
• DLiquid D

An iron nail is wrapped with copper wire connected to a D-cell battery, creating an electromagnet. Which modification will increase the magnetic field strength of this electromagnet?

• AIncreasing the number of wire coils wrapped around the iron nail
• BReplacing the iron nail core with a plastic drinking straw
• CRemoving one battery to decrease electric current
• DUnwinding the wire so it no longer touches the nail

The table below lists chemical formulas for four common household substances: Substance 1: $H_2O$ Substance 2: $O_2$ Substance 3: $NaCl$ Substance 4: $CO_2$ Which substance is classified as an elemental molecule rather than a compound?

• ASubstance 2 ($O_2$)
• BSubstance 1 ($H_2O$)
• CSubstance 3 ($NaCl$)
• DSubstance 4 ($CO_2$)

A 50 g ice cube at 0°C absorbs thermal energy from surrounding air until it melts completely into 50 g of liquid water at 0°C. What occurred at the molecular level during this phase change?

• AThermal energy broke intermolecular bonds holding ice molecules in fixed positions, witho…
• BWater molecules were converted into hydrogen and oxygen gas atoms
• CMolecules lost kinetic energy and froze into a solid lattice
• DSubatomic particles collapsed into atomic nuclei

A book rests motionless on a flat wooden desk. Which statement accurately describes the forces acting on the book?

• ADownward gravity is balanced by the upward normal force from the desk, yielding a net for…
• BNo forces act on the book because it is not moving
• CDownward gravity is the only force acting on the book
• DFriction is pulling the book sideways continuously

The speed of a light wave in vacuum is $3.0 \times 10^8\text{ m/s}$. When light enters a glass lens, its speed decreases to $2.0 \times 10^8\text{ m/s}$. What else happens to the light wave as it enters the glass?

• AIts wavelength decreases while its frequency remains unchanged
• BIts frequency doubles while its wavelength stays constant
• CIts energy increases to infinity
• DIt turns into a longitudinal mechanical sound wave

A student measures the mass and volume of four block samples to determine their densities: Block 1: Mass = 20 g, Volume = 10 cm³ Block 2: Mass = 30 g, Volume = 30 cm³ Block 3: Mass = 45 g, Volume = 15 cm³ Block 4: Mass = 50 g, Volume = 25 cm³ Water has a density of 1.0 g/cm³. Which block will sink most rapidly in water?

• ABlock 3
• BBlock 1
• CBlock 2
• DBlock 4

A microscope slide shows cells with a rigid outer boundary, large central vacuole, green oval organelles, and a distinct nucleus. Which cell type is being observed?

• APlant leaf cell
• BAnimal muscle cell
• CBacterial cell
• DHuman cheek cell

The chemical equation for photosynthesis is shown below: $$6 CO_2 + 6 H_2O + \text{Light Energy} \rightarrow C_6H_{12}O_6 + 6 O_2$$ How is the energy transformed during this process?

• ALight energy is converted into chemical energy stored in glucose bonds
• BChemical energy in glucose is converted into light and heat energy
• CNuclear energy is converted into mechanical kinetic energy
• DThermal energy is destroyed completely without transformation