Chapter 2: Matter Lecture Notes

Vocabulary flashcards covering the particle model of matter, classification of substances, states of matter, and physical and chemical changes from Chapter 2.

Matter

Anything that occupies space and has mass.

Atom

The basic building block of all matter.

Molecule

A particle consisting of two or more atoms covalently bonded together.

Mass

The amount of matter in an object, measured in grams, which cannot change on the basis of location.

Weight

The measure of gravity acting on the matter in an object, measured in newtons, which can change on the basis of location.

Density

The measure of mass per unit volume of a substance, represented by the formula $d = \frac{m}{V}$.

Brownian Motion

The constant, random motion of particles found in fluids that results from particle collisions.

Pure Substance

A material made of only one kind of element or compound.

Element

A pure substance that contains only one kind of atom, having the same atomic number.

Compound

A pure substance formed by two or more different elements that are chemically combined.

Mixture

A physical combination of two or more substances that may combine in variable proportions.

Homogeneous Mixture

A mixture that has a uniform appearance throughout, such as a solution.

Heterogeneous Mixture

A mixture that does not have a uniform appearance.

Solid

A state of matter characterized by a fixed shape, fixed volume, close particle spacing, vibrating particles, and low compressibility.

Liquid

A fluid state of matter that has a fixed volume, close particle spacing, low compressibility, and the ability to change shape to match its container.

Gas

A fluid state of matter characterized by particles that move rapidly and randomly, possessing high energy compared to solids and liquids of the same substance.

Plasma

A fluid state of matter that makes up the stars.

Fluid

Any state of matter with the ability to flow, which includes liquids, gases, and plasma.

Viscosity

A physical property that measures a fluid's resistance to flow.

Crystalline Solid

A solid comprised of particles arranged in regular, repeated patterns.

Luster

A physical property that describes how a material interacts with light.

Physical Change

A change that alters the physical appearance or state of a substance without altering its chemical composition.

Chemical Change

A change that alters the chemical composition of an item, forming new substances.

Freezing

A change of state that happens when liquid particles lose energy and form a solid.

Melting Point

The temperature at which a pure substance changes from a solid to a liquid, which is the same temperature as its freezing point.

Evaporation

The vaporization process that can occur at the surface of a liquid even when the liquid's temperature is below its boiling point.

Sublimation

The change of state that happens when solid particles gain energy and transition directly into a gas.

Deposition

The change of state that results when solids form directly from a vapor.

Condensation

A change of state from gas to liquid that involves particles losing energy.

Law of Conservation of Matter

The fundamental law stating that matter can neither be created nor destroyed, but can only change forms, ensuring the total amount of matter cannot change.