Physical Science Vocabulary 🪶📜🌕ִֶָ☾♡

The digital flashcard set for the Apologia Physical Science course! Happy studying!

Observation

the gathering of information using senses or with the aid of instruments

Hypothesis

a possible, testable explanation for one or more observations or a suggested, testable answer to a question

Controlled Experiment

an investigation in which the factors that influence the outcome are the same except for one — the factor being studied

Variable

a factor that can change in an experiment

Scientific Theory

a well-tested explanation of a phenomenon in the natural world

Scientific Law

a well-tested description of one phenomenon in the natural world that often includes mathematical terms

Inference

a logical conclusion drawn from observations, previous knowledge, and available information

Matter

anything that has mass and takes up space (has volume)

Atom

the smallest chemical unit of an element

Element

a pure substance that cannot be broken down into a simpler substance and contains only one type of atom

Compound

a pure substance that contains two or more elements chemically joined in a fixed proportion

Molecule

the smallest unit of a chemical compound, composed of two or more atoms bonded together

Solution

an evenly distributed mixture made by dissolving one substance in another

Solute

the substance in a solution that gets dissolved

Solvent

the substance in a solution in which the solute dissolves

Solid

the state of matter in which a substance has a definite shape and a definite volume

Liquid

the state of mater in which a substance has definite volume

Gas

the state of matter in which a substance has neither a definite shape nor definite volume

Density

the ratio of a substance’s mass to its volume (density = mass/volume)

Kinetic Energy

the energy an object has due to its motion

Valence Electrons

electrons that are in the highest energy level (the energy level farthest from the nucleus)

Reactants

substances that undergo a chemical change

Products

new substances formed as a result of a chemical change

Chemical Bond

a force of attraction between atoms or a group of atoms due to the sharing or transferring of electrons

Ion

an atom or group of atoms that has a positive or negative charge

Polar Molecule

a molecule that has slight positive and negative charges due to an imbalance in the way electrons are shared

Binary Compounds

compounds made of only two elements (bi)

Synthesis Reaction

a chemical reaction in which two or more substances react to form a single compound

Decomposition Reaction

a chemical reaction in which a compound breaks down into two or more simpler substances (opposite of synthesis reaction)

Combustion Reaction

a chemical reaction in which a substance reacts rapidly with oxygen, often producing heat and light

Chemical Energy

the energy stored in chemical bonds

Exothermic Reaction

a chemical reaction that releases energy to its surroundings

Endothermic Reaction

a chemical reaction that absorbs energy from its surroundings

Reference Point

a point against which motion is measured

Displacement

the distance an object travels plus the direction from the starting point

Vector Quantity

a physical measurement that contains both magnitude (number) and directional information

Scalar Quantity

a physical measurement that contains magnitude (number) and does not contain directional information

Average Speed

the ratio of the total distance traveled to the total time of the trip

Instantaneous Speed

the rate at which an object is moving at a given moment in time

Acceleration

the change in an object’s velocity over time

Force

a push or pull that acts on an object

Friction

a force that opposes motion, resulting when two objects rub against one another

Static Friction

friction that opposes the initiation of motion

Kinetic Friction

friction that opposes motion once the motion has already started

Free Fall

the motion of an object when it is falling solely under the influence of gravity

Inertia

the tendency of an object to resist changes in velocity

Newton’s First Law

an object in motion/at rest will stay in motion/at rest unless acted upon by an unbalanced force

Newton’s Second Law

when an object is acted on by one or more unbalanced forces, the net force is equal to the mass of the object times the resulting acceleration (f = ma)

Newton’s Third Law

for every action, there is an equal and opposite reaction