Classifying

States of Matter

Definite shape and volume Particles tightly packed together Expands when heated incompressible

Fluid in shape Takes the shape of the bottom of a container Incompressible Expands when heated

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

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

Classification of Matter

MixtureHomogeneousHeterogeneousPure SubstanceCompoundElement Separate Physically Separate Chemically

Matter that has a constant composition and distinct properties

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 **First letter in ALL chemical symbols are ALWAYS capitalize, second letter is ALWAYS lowercase

Two or more elements chemically combined in fixed proportions Has properties different than its components Can be separated by only chemical means (electricity & heat) Subscripts denote number of atoms Mg 3 N 2 Mg 3 (PO 4 ) 2 Numbers outside of the parentheses get multiplied in

Combination of two or more pure substances in which each pure substance retains its individual identities Do not have fixed proportions Can be created or separated by physical means

Composition of the mixture is the same throughout Also called a solution Mixed at the molecular level and has a single phase

Does not have uniform composition and the individual substances remain distinct

Distillation Separates homogeneous liquid-liquid mixtures using differences in boiling points Filtration Separates heterogeneous solid-liquid mixtures

Chromatography Separates homogeneous liquid-liquid mixtures based on differences in solubility and tendency to travel across the surface of another material Crystallization Separates homogeneous solid-liquid mixtures Results in a pure solid substance

Evaporation Allowing a solution (solid dissolved in a liquid) to “dry” Typically the liquid evaporates into the air Decant To pour a liquid, from one container to another, gently to not disturb the sediment