Classifying
States of Matter
Definite shape and volume Particles tightly packed together Expands when heated Incompressible (not compressible)
Fluid in shape Takes the shape of the bottom of a container Incompressible (not compressible) 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
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 **The first letter in ALL chemical symbols is ALWAYS capitalized, the second letter is ALWAYS lowercase Ex. Ca for Calcium and Fe for Iron
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 Mg 3 N 2 __Mg, __N Mg 3 (PO 4 ) 2 __Mg, __P,__O 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 Does not have fixed proportions (Air samples differ depending on aspects of location, altitude, population, etc or seawater samples differ upon location) Can be created or separated by physical means
MatterMixtureHomogeneousHeterogeneousPure SubstanceCompoundElement Separate Physically Separate Chemically (Page 3 of NTs)
Physical vs Chemical
Dissolving Homogeneous solid-liquid mixtures where the liquid phase is retained
Distillation Separates homogeneous liquid-liquid mixtures using differences in boiling points Chromatography Separates homogeneous liquid- liquid mixtures based on differences in solubility and tendency to travel across the surface of another material
Evaporation Allowing a solution (solid dissolved in a liquid) to “dry” Typically the liquid evaporates into the air Crystallization Separates homogeneous solid- liquid mixtures Results in a pure solid substance
Filtration Separates heterogeneous solid- liquid mixtures Decant To pour a liquid, from one container to another, gently to not disturb the sediment