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100+ Free CAST Grade 8 Practice Questions

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2026 Statistics

Key Facts: CAST Grade 8 Exam

Grades 5, 8, HS

CAST administered in grade 5, grade 8, and once in high school

cde.ca.gov CAASPP science

~2 hours

Untimed; estimated about two hours for three segments

caaspp-elpac.org CAST

32–34 + PTs

Segment A discrete items plus 2 performance tasks for student scores

Revised CAST Blueprint

3 domains

Physical, Life, Earth & Space Sciences with integrated ETS

CAST Blueprint

CA NGSS

Aligned to California Next Generation Science Standards grades 6–8

CDE CAST page

Free

State-funded CAASPP assessment; no family exam fee

Statewide assessment program

4 levels

Minimal, Developing, Proficient, Advanced; Grade 8 Proficient is 415–432

CDE CAST Range ALDs (2025–26 labels)

59 PEs

Item specifications cover 59 Performance Expectations for grade 8 form

CDE CAST Item Specifications

CAST Grade 8 is California’s free statewide CA NGSS science test (CDE/CAASPP), untimed (~2 hours), three science domains plus integrated engineering, four achievement levels.

Sample CAST Grade 8 Practice Questions

Try these sample questions to test your CAST Grade 8 exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In the middle school model of matter, which description of an atom is most accurate?
A.The smallest particle of an element that still has that element's properties
B.A molecule made of many different elements bonded together
C.A cell that can reproduce on its own
D.A force field that has no mass
Explanation: An atom is the basic unit of an element that retains the element's chemical identity. Molecules are groups of atoms; cells are living structures; atoms have mass.
2Which example is a molecule?
A.O₂, two oxygen atoms bonded together
B.A single proton alone in empty space
C.A pure copper sample described only as Cu atoms not bonded in a molecule
D.A sound wave traveling through air
Explanation: A molecule is two or more atoms bonded together. O₂ is a diatomic molecule of oxygen. A lone proton is a subatomic particle; sound is a wave, not a molecule.
3Which process is a chemical change?
A.Iron nails rusting when oxygen and water react with iron
B.Cutting aluminum foil into strips
C.Boiling pure water until it becomes steam
D.Dissolving sugar completely in hot tea
Explanation: Rusting forms new substances (iron oxides). Cutting, boiling, and dissolving are physical changes that do not create new chemical substances in the same way.
4Baking soda and vinegar react in a sealed, flexible container and produce a gas. If no mass escapes, how does the total mass after the reaction compare with the mass before?
A.It is the same because mass is conserved in a closed system
B.It must double because a gas formed
C.It must become zero because reactants are used up
D.It decreases automatically whenever temperature rises
Explanation: In a closed system, mass is conserved. Reactants rearrange into products, including gas, but total mass stays the same if nothing leaves.
5Which particle is negatively charged and occupies the region outside the nucleus in common middle school atom models?
A.Electron
B.Proton
C.Neutron
D.Alpha particle nucleus only
Explanation: Electrons are negatively charged and are modeled outside the nucleus. Protons are positive in the nucleus; neutrons are neutral in the nucleus.
6Plastic water bottles and synthetic fabrics are examples of synthetic materials. What does synthetic mean in this context?
A.Made by people using chemical processes, often from natural resources
B.Found only as pure elements in the Earth's crust
C.Always safer and more biodegradable than natural materials
D.Materials that cannot be melted or reshaped
Explanation: Synthetic materials are manufactured by people, often through chemical reactions that rearrange atoms from natural resources into new substances with useful properties.
7Kinetic energy is the energy of
A.position or height above Earth only
B.motion
C.chemical bonds stored in food only
D.sound waves that have already stopped
Explanation: Kinetic energy is energy associated with motion. Faster or more massive objects generally have more kinetic energy.
8A ball rests on a high shelf. Which type of energy is mainly associated with its position above the floor?
A.Kinetic energy
B.Gravitational potential energy
C.Thermal energy only
D.Sound energy
Explanation: Gravitational potential energy depends on mass and height in a gravitational field. A raised ball has potential energy that can convert to kinetic energy if it falls.
9Heat flows from a hot metal spoon into cooler soup mainly by which process when they are in contact?
A.Conduction
B.Reflection of light
C.Nuclear fusion
D.Photosynthesis
Explanation: Conduction is energy transfer through direct contact as particles collide. Thermal energy moves from warmer matter to cooler matter until temperatures are closer.
10A force of 12 N to the right and a force of 5 N to the left act on the same object along a straight line. What is the net force?
A.17 N to the right
B.7 N to the right
C.7 N to the left
D.12 N to the left
Explanation: Net force is the vector sum of forces. Opposite forces subtract: 12 N right − 5 N left = 7 N to the right.

About the CAST Grade 8 Exam

The California Science Test (CAST) Grade 8 is California’s statewide CAASPP science assessment for grade 8 students. It measures the California Next Generation Science Standards (CA NGSS) for grades 6–8 across Physical Sciences, Life Sciences, and Earth and Space Sciences, with Engineering, Technology, and Applications of Science integrated by context. The computer-based form uses discrete items and performance tasks and is untimed (about two hours estimated). OpenExamPrep free MCQ practice is an English-language study aid aligned to CAST domains and CA NGSS—not official secure content or a full simulation of multi-part performance tasks.

Assessment

Question count not published by the exam provider

Time Limit

Untimed; estimated about two hours for all three segments (CDE/CAASPP).

Passing Score

No pass/fail score. Four overall achievement levels: Level 1 Minimal, Level 2 Developing, Level 3 Proficient, Level 4 Advanced (labels adopted by the SBE and used from 2025–26 reporting; formerly Standard Not Met / Nearly Met / Met / Exceeded). Cut scores unchanged: Grade 8 scale 350–450, Proficient 415–432, Advanced 433–450. Domain results use Above Proficient / At or Near Proficient / Below Proficient.

Exam Fee

Free to students and families; CAST is state-funded and administered through California public schools as part of CAASPP. (California Department of Education (CAASPP); operational delivery via the CAASPP contractor (ETS))

CAST Grade 8 Exam Content Outline

about one-third (~8–10 Segment A items)

Physical Sciences (with integrated ETS)

Matter and chemical reactions, forces and motion, energy, and waves at middle school depth; Engineering, Technology, and Applications of Science items assigned by stimulus context.

about one-third (~8–10 Segment A items)

Life Sciences (with integrated ETS)

Cells and organisms, ecosystems, heredity, and biological evolution with SEPs and CCCs at grades 6–8 depth.

about one-third (~8–10 Segment A items)

Earth and Space Sciences (with integrated ETS)

Earth’s place in the universe, Earth’s systems, weather and climate, and Earth and human activity, including Environmental Principles and Concepts context where appropriate.

How to Pass the CAST Grade 8 Exam

What You Need to Know

  • Passing score: No pass/fail score. Four overall achievement levels: Level 1 Minimal, Level 2 Developing, Level 3 Proficient, Level 4 Advanced (labels adopted by the SBE and used from 2025–26 reporting; formerly Standard Not Met / Nearly Met / Met / Exceeded). Cut scores unchanged: Grade 8 scale 350–450, Proficient 415–432, Advanced 433–450. Domain results use Above Proficient / At or Near Proficient / Below Proficient.
  • Assessment: Question count not published by the exam provider
  • Time limit: Untimed; estimated about two hours for all three segments (CDE/CAASPP).
  • Exam fee: Free to students and families; CAST is state-funded and administered through California public schools as part of CAASPP.

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

CAST Grade 8 Study Tips from Top Performers

1Use official CAST practice and training tests on the CAASPP portal so students learn tools, item types, and the testing interface.
2Review CA NGSS Performance Expectations for grades 6–8—the Grade 8 form samples the middle school band.
3Practice interpreting data tables, models, and force/energy diagrams with claim–evidence–reasoning explanations.
4Include engineering design prompts (criteria, constraints, trade-offs) because ETS PEs are integrated into domain scores.
5Connect Earth systems topics (weather, plate tectonics, human impacts) with quantitative reasoning and systems thinking.
6Use short, frequent practice across the year rather than cramming only in the spring window.

Frequently Asked Questions

What is CAST Grade 8?

CAST is California’s statewide science assessment in the CAASPP System. Grade 8 assesses CA NGSS Performance Expectations from grades 6–8 using three-dimensional items that integrate practices, core ideas, and crosscutting concepts.

Who takes CAST?

Students in grades 5 and 8 and once in high school (grade 10, 11, or 12) take CAST unless their IEP designates the California Alternate Assessment for Science.

How long is CAST?

CAST is untimed. CDE/CAASPP estimate about two hours for all three segments.

What domains are scored?

Students receive an overall score and domain scores for Physical Sciences, Life Sciences, and Earth and Space Sciences. Engineering items are assigned to a science domain based on stimulus context (CAST blueprint).

Is CAST free?

Yes. CAST is state-funded and administered through public schools at no cost to families for standard administration.

What language is the CAST given in?

The CAST is delivered in English. Eligible students may receive the Spanish stacked–dual language designated support, which displays a full Spanish translation of each item above the English version, and CDE publishes non-embedded translated CAST test directions in sixteen additional languages. OpenExamPrep practice questions are English-language only.

Are these practice questions official CAST items?

No. OpenExamPrep questions are English-language MCQ study adaptations aligned to CA NGSS and CAST domains. They do not reproduce secure items or fully simulate multi-part performance tasks and technology-enhanced item types.