Classifying

States of Matter

Solid Definite shape and volume Particles tightly packed together Expands when heated Incompressible (not compressible)

Liquid Fluid in shape Takes the shape of the bottom of a container Incompressible (not compressible) Expands when heated

Gas Particles can move freely in all directions Diffuse to fill container Take the shape of the container Particles are far apart Easily compressed

Gas is mostly empty space. Water Vapor

Gas vs Vapor Gas Vapor Substance in the gaseous state at room temperature Example: Oxygen Gaseous state of a substance that is solid or liquid at room temperature Example: water vapor

Classification of Matter

Substance Matter that has a constant composition and distinct properties

Element Substance that cannot be separated into simpler substances Most occur naturally on Earth (118 to date) Ex: Gold, Carbon, Hydrogen

Atomic number Chemical symbol Atomic mass Chemical Name **The first letter in ALL chemical symbols is ALWAYS capitalized, the second letter is ALWAYS lowercase Ex. Ca for Calcium and Fe for Iron

Compound Two or more elements chemically combined Has properties different than its components Can be separated only by chemical means (electricity & heat) Subscripts denote number of atoms Mg3N2 __Mg, __N Mg3(PO4)2 __Mg, __P,__O Numbers outside of the parentheses get multiplied in 3 2 3 2 8