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🇺🇸 ACT (American College Testing) · flashcards
ACT (American College Testing) Science Flashcards
50 question-and-answer cards covering Science as it is examined in ACT (American College Testing). 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the Science deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
What distinguishes prokaryotic cells from eukaryotic cells?
Prokaryotes lack a membrane-bound nucleus and membrane-bound organelles; eukaryotes have both.
What is the role of the mitochondria in a cell?
It is the site of cellular respiration, producing ATP (the cell's energy).
What is the pH range of acids, bases, and neutral solutions?
Acids: pH below 7; neutral: pH 7; bases: pH above 7.
What distinguishes an exothermic reaction from an endothermic reaction?
Exothermic reactions release heat to surroundings; endothermic reactions absorb heat from surroundings.
In an atom, what are the charges and locations of protons, neutrons, and electrons?
Protons (positive) and neutrons (neutral) are in the nucleus; electrons (negative) orbit outside the nucleus.
What determines an element's atomic number?
The number of protons in its nucleus.
What are isotopes?
Atoms of the same element with the same number of protons but different numbers of neutrons (different mass numbers).
What is the difference between an ionic bond and a covalent bond?
Ionic bonds form by transfer of electrons between atoms; covalent bonds form by sharing electrons.
What is the law of conservation of mass in a chemical reaction?
Mass is neither created nor destroyed; the total mass of reactants equals the total mass of products.
State Newton's second law of motion as a formula.
F = ma (force equals mass times acceleration).
What is Newton's first law of motion?
An object at rest stays at rest and an object in motion stays in motion at constant velocity unless acted on by a net external force (inertia).
What is the difference between speed and velocity?
Speed is a scalar (magnitude only); velocity is a vector (magnitude and direction).
What is the formula for kinetic energy?
KE = ½mv² (half the mass times velocity squared).
What is the relationship between a wave's frequency and its wavelength at constant speed?
They are inversely related: as wavelength increases, frequency decreases (v = fλ).
What is the acceleration due to gravity near Earth's surface?
Approximately 9.8 m/s² directed downward.
What is the difference between conduction, convection, and radiation?
Conduction: heat transfer through direct contact; convection: transfer through fluid movement; radiation: transfer via electromagnetic waves (no medium needed).
What are the three layers of Earth's interior from outside to inside?
Crust, mantle, and core (the core has a liquid outer core and solid inner core).
What drives the movement of Earth's tectonic plates?
Convection currents in the mantle.
What are the three main types of rock and how does each form?
Igneous (from cooled magma/lava), sedimentary (from compacted sediments), metamorphic (from heat/pressure altering existing rock).
List the inner (terrestrial) planets of our solar system in order from the Sun.
Mercury, Venus, Earth, Mars.
What causes Earth's seasons?
The tilt of Earth's axis (about 23.5°) relative to its orbital plane, changing the angle and duration of sunlight as Earth orbits the Sun.
What is the greenhouse effect?
The trapping of outgoing infrared (heat) radiation by atmospheric gases (e.g., CO2, water vapor), warming Earth's surface.
What does the geologic principle of superposition state?
In undisturbed rock layers, older layers lie at the bottom and progressively younger layers lie above.
What is the difference between weather and climate?
Weather is short-term atmospheric conditions at a place; climate is the long-term average of weather patterns over years.
What this deck covers
The Science deck follows the ACT (American College Testing) Science syllabus — 4 chapters and 14 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 12.5 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 89 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
Science flashcards FAQ
How many Science flashcards are in this ACT (American College Testing) deck?
50 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these ACT (American College Testing) flashcards free?
Yes. The preview here is free to read with no signup, and the full 50-card deck is free inside the Examius app.
What do the Science cards cover?
They follow the ACT (American College Testing) Science syllabus — 4 chapters and 14 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.