Chemistry - Ch 3 Vocab

States of Matter

All matter that exists naturally on Earth can be classified as one of three physical forms (solids, liquids, gas)

Solid

A form of matter that has its own definite shape and volume

Liquid

A form of matter that flows, has constant volume, and takes the shape of its container

Gas

A form of matter that not only flows to conform to the shape of its container but also fills the entire volume of its container

Vapor

The gaseous state of a substance that is a solid or a liquid at room temperature

Physical Property

A characteristic of matter that can be observed or measured without changing the sample’s composition

Extensive Properties

Dependent on the amount of substance present (Ex: mass)

Intensive Properties

Independent of the amount of substance present (Ex: density)

Chemical Properties

The ability or inability of a substance to combine with or change into one or more other substances

Physical Change

A change that alters a substance without changing its composition

Phase Change

A transition of matter from one state to another

Chemical Change

A process that involves one or more substances changing into new substances

Law of Conservation of Mass

States that mass is neither created nor destroyed during a chemical reaction - it is conserved

Mixture

A combination of two or more pure substances in which each pure substance retains its individual chemical properties

Heterogeneous Mixture

A mixture that does not blend smoothly throughout and in which the individual substances remain distinct

Homogeneous Mixture

A mixture that has constant composition throughout; it always has a single phase

Solution

Another name for a homogeneous mixture

Filtration

A technique that uses a porous barrier to separate a solid from a liquid

Distillation

A physical separation technique that is based on differences in the boiling points of the substances involved

Crystallization

A separation technique that results in the formation of pure solid particles of a substance from a solution containing the dissolved substance

Sublimation

The process during which a solid changes to a vapor without melting, i.e. without going through the liquid phase

Chromatography

A technique that separates the components of a mixture dissolved in either a gas or a liquid based on the ability of each component to travel or to be drawn across the surface of a fixed substrate

Element

A pure substance that cannot be separated into simpler substances by physical or chemical means

Periodic Table

Organizes the elements into a grid of horizontal rows called periods and vertical rows called groups or families

Compound

Made up of two or more different elements that are combined chemically

Law of Definite Proportions

States that a compound is always composed of the same elements in the same proportion by mass, no matter how large or small the sample

Percent by Mass

The ratio of the mass of each element to the total mass of the compound expressed as a percentage

Law of Multiple Proportions

States that when different compounds are formed by a combination of the same elements, different masses of one element combine with the same fixed mass of the other element in a ratio of small whole numbers