ACT PreP 2025/2026 | OFFICIAL eXAM MATerIAL
WITH STUDY GUIDe AND PrACTICe TeST | VerIFIeD
QUeSTIONS AND ANSWerS FrOM THe reAL eXAM |
UPDATeD eDITION | PrOVeN SUCCeSS rATe
1. Atmospheric pressure - ANSWER The pressure exerted by the atmosphere
on every part of Earth's surface; approximately 10 newtons per square
centimeter
2. Atom - ANSWER The smallest part of an element that is recognizable as
that element
3. Barometer - ANSWER An instrument that measures atmospheric pressure
4. Base - ANSWER A compound that releases hydroxide ions in water; has a
pH of more than 7; is sometimes called an alkali
5. Boiling point - ANSWER The temperature at which additional thermal
energy causes a substance to change from a liquid to a vapor
6. Calorie - ANSWER A quantity of heat energy; the amount needed to raise
the temperature of one gram of water 1° C
7. Carbohydrate - ANSWER An organic compound-like sugar or starch that
contains carbon, hydrogen, and oxygen in the ratio of 1:2:1; the human
body's main source of energy
8. Carcinogen - ANSWER A cancer-causing agent
,9. Carnivore - ANSWER Meat-eater
10.Catalyst - ANSWER A substance that speeds up a chemical reaction without
being changed by the reaction
11.Cell - ANSWER The lowest-level structure of any living organism that can
perform all the functions of life, including reproduction
12.Chlorophyll - ANSWER The main pigment in plants that captures light
energy during photosynthesis
13.Compound - ANSWER A substance composed of two or more chemically
bonded elements
14.Concentration - ANSWER The exact amount of substance dissolved in a
given amount of solvent; refers to a solution
15.Condensation - ANSWER The process whereby a decrease in energy causes
vapor particles to return to a liquid phase
16.Conductor - ANSWER A material that allows heat or electricity to flow
through it with minimal resistance
17.Control - ANSWER A sample in which no variables are tested, thus serving
as a basis for comparison
18.Control variable - ANSWER A variable that stays constant in an experiment,
allowing the effect of another variable to be measured
19.Convection - ANSWER The circulation of fluid caused by warm fluid rising
and cool fluid sinking
20.Density - ANSWER In a physics sense, the amount of mass per unit volume;
in a more general sense, the quantity per unit area or volume
, 21.Diffusion - ANSWER The scattering of light; the spreading of a liquid or gas
from areas of higher concentration to areas of lower concentration
22.DNA - ANSWER Nucleic acid in the cells of an organism; contains the
genes of an organism and transmits these to future generations
23.Ecological succesion - ANSWER A sequence of changes in the plant and/or
animal life of a region over time
24.Electron - ANSWER A negatively charged fundamental atomic particle
25.Element - ANSWER A substance consisting of exactly one type of atom
26.Erosion - ANSWER Wearing away; typically the washing away of sand or
rock by running water or wind
27.Evaporation - ANSWER The changing of a fluid into gas
28.Fossil - ANSWER The preserved remains of a very old organism
29.Frequency - ANSWER The number of cycles per unit time of a repeating
phenomenon
30.Glucose - ANSWER A simple sugar that is broken down to provide energy
to an organism
31.Habitat - ANSWER The part of an ecosystem where a plant or animal
naturally grows or lives
32.Herbivore - ANSWER An animal that eats only plants
Hormone - ANSWER A chemical substance secreted by a gland of the body that
affects other parts of the body
, Humidity - ANSWER The amount of water vapor in the air
Hypothesis - ANSWER A statement that is a proposed explanation of a scientific
phenomenon
Infrared radiation - ANSWER Electromagnetic waves whose wavelength is longer
than that of visible light
Insulator - ANSWER A substance that blocks the flow of heat or electricity
Ion - ANSWER A molecule or atom that has become charged by either gaining or
losing an electron
Isotope - ANSWER A variety of an element with the same number of protons per
atom but a different number of neutrons
Kinetic energy - ANSWER The energy of an object due to its motion
Melting point - ANSWER The temperature at which additional thermal energy
breaks the chemical bonds holding a substance together and causes the substance
to change from the solid to a liquid state
Molecule - ANSWER The smallest unit of a chemical compound
Neutron - ANSWER A fundamental atomic particle that has no charge
Ore - ANSWER A piece of rock from which metal can be profitably extracted
Osmosis - ANSWER The movement of liquid through a membrane
Parasite - ANSWER An organism that invades another organism and feeds off it
WITH STUDY GUIDe AND PrACTICe TeST | VerIFIeD
QUeSTIONS AND ANSWerS FrOM THe reAL eXAM |
UPDATeD eDITION | PrOVeN SUCCeSS rATe
1. Atmospheric pressure - ANSWER The pressure exerted by the atmosphere
on every part of Earth's surface; approximately 10 newtons per square
centimeter
2. Atom - ANSWER The smallest part of an element that is recognizable as
that element
3. Barometer - ANSWER An instrument that measures atmospheric pressure
4. Base - ANSWER A compound that releases hydroxide ions in water; has a
pH of more than 7; is sometimes called an alkali
5. Boiling point - ANSWER The temperature at which additional thermal
energy causes a substance to change from a liquid to a vapor
6. Calorie - ANSWER A quantity of heat energy; the amount needed to raise
the temperature of one gram of water 1° C
7. Carbohydrate - ANSWER An organic compound-like sugar or starch that
contains carbon, hydrogen, and oxygen in the ratio of 1:2:1; the human
body's main source of energy
8. Carcinogen - ANSWER A cancer-causing agent
,9. Carnivore - ANSWER Meat-eater
10.Catalyst - ANSWER A substance that speeds up a chemical reaction without
being changed by the reaction
11.Cell - ANSWER The lowest-level structure of any living organism that can
perform all the functions of life, including reproduction
12.Chlorophyll - ANSWER The main pigment in plants that captures light
energy during photosynthesis
13.Compound - ANSWER A substance composed of two or more chemically
bonded elements
14.Concentration - ANSWER The exact amount of substance dissolved in a
given amount of solvent; refers to a solution
15.Condensation - ANSWER The process whereby a decrease in energy causes
vapor particles to return to a liquid phase
16.Conductor - ANSWER A material that allows heat or electricity to flow
through it with minimal resistance
17.Control - ANSWER A sample in which no variables are tested, thus serving
as a basis for comparison
18.Control variable - ANSWER A variable that stays constant in an experiment,
allowing the effect of another variable to be measured
19.Convection - ANSWER The circulation of fluid caused by warm fluid rising
and cool fluid sinking
20.Density - ANSWER In a physics sense, the amount of mass per unit volume;
in a more general sense, the quantity per unit area or volume
, 21.Diffusion - ANSWER The scattering of light; the spreading of a liquid or gas
from areas of higher concentration to areas of lower concentration
22.DNA - ANSWER Nucleic acid in the cells of an organism; contains the
genes of an organism and transmits these to future generations
23.Ecological succesion - ANSWER A sequence of changes in the plant and/or
animal life of a region over time
24.Electron - ANSWER A negatively charged fundamental atomic particle
25.Element - ANSWER A substance consisting of exactly one type of atom
26.Erosion - ANSWER Wearing away; typically the washing away of sand or
rock by running water or wind
27.Evaporation - ANSWER The changing of a fluid into gas
28.Fossil - ANSWER The preserved remains of a very old organism
29.Frequency - ANSWER The number of cycles per unit time of a repeating
phenomenon
30.Glucose - ANSWER A simple sugar that is broken down to provide energy
to an organism
31.Habitat - ANSWER The part of an ecosystem where a plant or animal
naturally grows or lives
32.Herbivore - ANSWER An animal that eats only plants
Hormone - ANSWER A chemical substance secreted by a gland of the body that
affects other parts of the body
, Humidity - ANSWER The amount of water vapor in the air
Hypothesis - ANSWER A statement that is a proposed explanation of a scientific
phenomenon
Infrared radiation - ANSWER Electromagnetic waves whose wavelength is longer
than that of visible light
Insulator - ANSWER A substance that blocks the flow of heat or electricity
Ion - ANSWER A molecule or atom that has become charged by either gaining or
losing an electron
Isotope - ANSWER A variety of an element with the same number of protons per
atom but a different number of neutrons
Kinetic energy - ANSWER The energy of an object due to its motion
Melting point - ANSWER The temperature at which additional thermal energy
breaks the chemical bonds holding a substance together and causes the substance
to change from the solid to a liquid state
Molecule - ANSWER The smallest unit of a chemical compound
Neutron - ANSWER A fundamental atomic particle that has no charge
Ore - ANSWER A piece of rock from which metal can be profitably extracted
Osmosis - ANSWER The movement of liquid through a membrane
Parasite - ANSWER An organism that invades another organism and feeds off it
