Chapter 5 of 813% of exam

General Science

General Science covers a broad range of topics from life science, physical science, and earth and space science. Questions test general knowledge you would gain from middle and high school courses. While this subtest is not part of the AFQT, it counts toward line scores for many technical military jobs. A broad review across biology, chemistry, physics, and earth science prepares you best.

Life Science and Biology

Life science covers cells, the human body, genetics, and living systems. Knowing basic structures and functions answers many questions.

Know cell parts
The nucleus stores genetic material, mitochondria release energy, and chloroplasts carry out photosynthesis in plants.
Understand body systems
The circulatory system pumps blood, the respiratory system handles breathing, and the digestive system processes food.
Learn basic genetics
A gene is a segment of DNA that carries inherited traits from parents to offspring.
Recognize blood components
White blood cells fight infection, red blood cells carry oxygen, and platelets help blood clot.

Chemistry Fundamentals

Chemistry topics include atoms, elements, compounds, and the difference between physical and chemical changes.

Know atomic structure
Protons carry positive charge and neutrons no charge in the nucleus, while electrons carry negative charge around it.
Read chemical formulas
Water is H2O, carbon dioxide is CO2, and table salt is NaCl.
Distinguish changes
A chemical change like rusting forms a new substance, while melting or boiling is a physical change.
Understand states of matter
Matter exists as solid, liquid, or gas, and changes state when energy is added or removed.

Physics and Energy

Physical science covers forces, motion, and energy. Basic principles explain how objects move and how energy changes form.

Define forces
Gravity pulls objects toward Earth's center, and friction opposes motion between surfaces.
Know energy types
Potential energy is stored by position or state, while kinetic energy is the energy of motion.
Understand energy conversion
Energy changes form, as when a stretched spring's potential energy becomes motion.
Recall temperature points
Pure water freezes at 0 degrees Celsius and boils at 100 degrees Celsius at sea level.

Earth and Space Science

Earth science covers the planet's structure, weather, and the solar system. A few key facts cover many questions.

Know Earth's layers
The atmosphere is the surrounding gases, the lithosphere is the solid crust, and the hydrosphere is the water.
Order the planets
Mercury is closest to the Sun, followed by Venus, Earth, and Mars.
Understand the water cycle
Evaporation turns liquid water to vapor, and condensation turns vapor back to liquid.
Recognize measurement scales
The Richter scale measures earthquake magnitude, a common earth-science fact.

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Last updated: November 2026

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