Fundamental Concepts of Matter and Energy

Matter

anything that has mass and occupies volume

Mass

the amount of matter in a substance or object

Volume

measure of the amount of space that a substance or object occupies

Weight

the force of gravity acting on an object

Density

ratio of mass to volume in a substance

Bonds

attractive forces between atoms

Atom

Smallest part of an element that retains properties of the element

Elements

Contain only one kind of atom

Homogeneous

A sample of matter that has the same properties throughout

Compounds

When two or more elements combine in fixed proportions by mass

Substance

Any variety of matter that has a definite, unvarying set of properties and for which all samples have identical composition

Mixtures

Usually contain two or more kinds of matter in varying proportions

Homogenous mixtures

uniform in composition

Heterogeneous mixtures

not uniform in composition

Compounds vs. Mixtures

Compounds have a single set of properties; Mixtures have the properties of each of its components

Alloys

Mixtures of certain metals

Energy

defined as the ability, or capacity to do work

Potential energy (PE)

energy a body possesses due to its position with respect to another body

Chemical Energy

Type of potential energy stored in the bonds that result from the attractive forces between particles

Kinetic Energy (KE)

energy of motion

Law of the conservation of energy

total amount of energy in a system is constant

Temperature

measure of the average kinetic energy of a system

Heat

measure of the total energy in a system

Heat of Fusion

heat that is required to melt a given quantity of a solid

Heat of vaporization

heat required to boil a quantity of liquid

Solution

homogeneous mixture consisting of a solvent and a solute

Saturated

a solution in which the normal maximum amount of solute has dissolved in a given amount of solvent at a specific temperature

Unsaturated

a solution in which less than the normal maximum amount of solute has dissolved in a given amount of solvent at a specific temperature

Supersaturated

a solution in which more than the normal maximum amount of solute has dissolved in a given amount of solvent at a specific temperature

Physical Properties

describe qualities of a substance that can be demonstrated without changing the composition of the substance

Physical Change

form of a substance changes but not the identity of the matter

Chemical Properties

describes how matter behaves when it changes into another kind of matter

Chemical change

when one or more substances change into one or more new substances