Matter and Change

Section 1: Chemistry is a Physical Science

Chemistry: the study of composition, structure, and properties of matter, the processes that matter undergoes, and the energy changes that accompany these processes

Chemical: any substance that has a definite composition

Six Branches of Chemistry: Organic, Inorganic, Physical, Analytical, Biochemistry, Theoretical chemistry

Two types of research: Basic and Applied

Section 2: Matter and its Properties

Atoms: smallest unit of an element that maintains the chemical identity of that element

Element: a pure substance that cannot be broken down into simpler, stable substances and is made of one type of atoms

Compound: a substance that can be broken down into simple stable substances. Made from atoms of two or more elements that are chemically bonded

2 types of Properties: Extensive and Intensive

Physical Properties and Physical Changes

States of matter

Chemical Properties and Changes

A mixture is a blend of two or more kinds of matter, each retains its own identity and properties. There are two types of mixtures: Homogenous and Heterogenous. Some mixtures are uniform in composition which are homogeneous mixtures . They have the same proportion of components throughout. Homogeneous mixtures are also called solutions. Other mixtures are not uniform throughout which are heterogeneous mixtures . For example, in a mixture of clay and water, heavier clay particles concentrate near the bottom of the container.

A pure substance is homogenous as a single entity. A pure substance has a fixed composition. Every sample of a given pure substance has exactly the same characteristic properties. Every sample of a given pure substance has exactly the same composition.