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25 multiple-choice questions and 13 flashcards on General Science, about 8% of the ASVAB bank. Every one carries a written rationale.
General Science is one of 11 chapters in CoStudy's ASVAB bank, and it holds 25 of the bank's 300 multiple-choice questions — roughly 8% of the total. That proportion is not arbitrary: chapters follow the certifying body's published exam outline, and the number of questions in each is set by that domain's published weight, so the share of your practice time this chapter takes matches the share of the real exam it accounts for.
Studying by chapter is worth doing once you have a diagnostic score. A single overall percentage tells you whether you are close; it does not tell you which domain is dragging. Working a weak chapter in isolation, and re-testing it in isolation, is the fastest way to move a score that has stalled — and it is why the mock exams in CoStudy report by domain rather than as one number.
10 questions drawn from this chapter, with the full rationale shown — the controlling principle behind the right answer, and why each wrong option tempts and fails.
Which of the following changes is chemical rather than physical?
Answer: B — Iron rusting after long exposure to moist air
B) Correct — rusting bonds iron with oxygen to make a new substance with new properties, the hallmark of chemical change. A) tempts because the appearance changes, but melting only changes state. C) tempts because the salt seems to vanish, yet it can be recovered unchanged by evaporation. D) tempts because the wire is permanently altered in shape, which is still physical.
On the periodic table, elements in the same column generally share what property?
Answer: D — Number of valence electrons
A) Mass changes down a group. D) Group members share valence electron count, which drives chemistry. C) Neutron counts vary. B) Density varies widely.
Two continental plates push directly against one another over millions of years. The MOST likely surface result is which of the following?
Answer: D — A high mountain range raised by the crumpling crust
D) Correct — continental collision has nowhere to sink light crust, so the crust thickens and folds upward into mountains. B) tempts because rifts are dramatic plate features, but they mark divergence, not collision. C) tempts because trenches do form at convergent margins, yet subduction needs dense oceanic crust. A) tempts by describing a transform boundary instead.
Two pea plants heterozygous for a single trait are crossed. If the allele for tall is dominant, the expected phenotype ratio of tall to short offspring is which of the following?
Answer: C — 3 tall to 1 short, a dominance outcome
C) Correct — a Tt by Tt cross gives TT, Tt, Tt and tt, so three of four show the dominant trait. A) tempts because it matches the genotype split of a test cross with a recessive parent. B) tempts by assuming blending inheritance, which is not simple dominance. D) tempts because dominance masks the recessive allele, but a homozygous recessive offspring is still possible.
A ball at the top of a hill primarily has which type of energy?
Answer: C — Gravitational potential
A) Kinetic energy is for moving objects. B) Thermal involves temperature. C) Stationary height gives gravitational potential energy. D) Chemical is stored in bonds.
Photosynthesis converts which inputs into glucose?
Answer: B — CO₂ + water + sunlight
A) Glucose is the OUTPUT, not input. B) Correct — plants take in carbon dioxide, water, and sunlight to produce glucose + oxygen. C) Nitrogen is a separate cycle. D) Glucose is the product.
Newton's 2nd Law states:
Answer: B — F = ma
A) That's momentum, not force. B) Correct — force equals mass times acceleration. C) Einstein's mass-energy equivalence. D) Ideal gas law.
Which best distinguishes weight from mass?
Answer: C — Weight depends on gravity; mass does not
A) Common misconception — they differ. B) Reversed. C) Weight = mass × gravity, so weight changes with location; mass is constant. D) Units are reversed.
The atomic number of an element equals:
Answer: C — Number of protons in the nucleus
A) That's the neutron count, separate. B) That's valence electrons. C) Correct — atomic number = proton count = element identity. D) That's atomic mass.
Which organelle is responsible for producing most of a cell's ATP?
Answer: D — Mitochondrion
A) Ribosomes synthesize proteins. B) Lysosomes break down waste. C) Golgi packages proteins. D) Mitochondria run cellular respiration and produce ATP.
4 cards from the 13 in this chapter.
Speed of light in vacuum?
~3 × 10⁸ m/s (or 300,000 km/s).
Atomic number = ?
Number of protons in nucleus.
Force = ?
Mass × acceleration. F = ma. (Newton's 2nd law.)
Name the layers of Earth's atmosphere from the surface upward.
Troposphere, stratosphere, mesosphere, thermosphere, exosphere. • Weather occurs in the troposphere and the ozone layer sits in the stratosphere.
These are a sample. The full General Science chapter runs 38 items with per-chapter progress tracking, on the web and in the iOS app.