LCPS Physical Science 8 Unit 1 Matter Vocabulary

Vocabulary flashcards for LCPS Physical Science 8 Unit 1 covering describing matter, states of matter, kinetic molecular theory, phase changes, physical and chemical changes, elements, compounds, and mixtures.

Matter

Anything that has mass and takes up space.

Mass

The amount of matter in an object. (Mass is usually measured in grams or kilograms.)

Volume

The amount of space an object or substance takes up. (Volume is usually measured in milliliters or centimeters cubed)

Physical property

A characteristic that can be observed or measured without changing a substance into a new substance.

Chemical property

A characteristic that describes a substance's ability to form new substances.

Density

The amount of mass in a given volume. Density equals mass divided by volume. (Density is usually measured in $\text{g/mL}$ or $\text{g/cm}^3$)

Conductivity

How well a material allows thermal energy or electric current to pass through it.

Solubility

The ability of a substance to dissolve in a particular solvent.

Reactivity

How readily a substance interacts chemically with another substance.

State of matter

A form of matter determined by particle arrangement, spacing, and motion.

Solid

A state with a definite shape and definite volume. Its particles vibrate in fixed positions.

Liquid

A state with a definite volume but no definite shape. Its particles slide past one another.

Gas

A state with no definite shape or volume. Its particles are far apart and move freely.

Plasma

A gas-like state containing positive ions and free electrons. Stars and lightning contain plasma.

Kinetic molecular theory

The explanation that matter is made of particles in constant motion. Warmer particles move faster on average.

Phase change

A physical change from one state of matter to another; the substance remains the same.

Melting

The change from solid to liquid.

Freezing

The change from liquid to solid.

Vaporization

The change from liquid to gas. Vaporization includes evaporation and boiling.

Evaporation

The change from a liquid to a gas that occurs only at the surface of a liquid and can happen below the boiling point.

Boiling

The change from a liquid to a gas that occurs throughout a liquid at its boiling point.

Condensation

The change from gas to liquid.

Heating curve

A graph showing temperature as energy is added. Flat sections show phase changes.

Physical change

A change in size, shape, appearance, or state that does not form a new substance.

Chemical change

A change in which one or more new substances form.

Precipitate

A solid that forms when two solutions undergo a chemical change.

Element

A pure substance made of only one type of atom.

Compound

A pure substance made of two or more different elements chemically bonded in a fixed ratio.

Mixture

Two or more substances physically combined, not chemically bonded, and separable by physical means.