MatterMatter

Key Questions:Key Questions:What’s the difference between an element, What’s the difference between an element,

compound, and mixture?compound, and mixture?How are the particles different in a solid, liquid, and How are the particles different in a solid, liquid, and

gas?gas?

You already reviewed…You already reviewed…

Chemical and Physical ChangesChemical and Physical Changes Indicators of chemical change:Indicators of chemical change:

BubblesBubbles Color changeColor change LightLight Can’t go back to starting materialsCan’t go back to starting materials

Element/Compound/MixtureElement/Compound/Mixture Changes of StateChanges of State

ElementsElements

A substance which contains only one A substance which contains only one kindkind of atom:  lead (Pb), silver (Ag), of atom:  lead (Pb), silver (Ag), hydrogen (Hhydrogen (H22), oxygen (O), oxygen (O22). ).

CompoundsCompounds

A substance which A substance which contains two or contains two or more kinds of more kinds of atoms:  atoms:  carbon dioxide carbon dioxide

(CO(CO22), calcium ), calcium oxide (CaO), oxide (CaO), sodium hydroxide sodium hydroxide (NaOH)(NaOH)

MixturesMixtures

Substances held together by Substances held together by physical forcesphysical forces, not chemical. , not chemical. The individual molecules enjoy being The individual molecules enjoy being

near each other, but their fundamental near each other, but their fundamental chemical structure does not change chemical structure does not change when they enter the mixture. when they enter the mixture.

Solids, Liquids and Solids, Liquids and GassesGasses

Matter commonly Matter commonly exists in one of three exists in one of three states of matterstates of matter

SolidSolid: Definite shape, : Definite shape, particles are packed particles are packed close togetherclose together

LiquidLiquid: Definite : Definite volume, particles are volume, particles are spaced apartspaced apart

GasGas: Indefinite shape : Indefinite shape and volume, particles and volume, particles widely spacedwidely spaced

PlasmaPlasma

PlasmaPlasma: an ionized gas, a gas into which : an ionized gas, a gas into which sufficient energy is provided to free sufficient energy is provided to free electrons from atoms or molecules from atoms or molecules

Freezing / MeltingFreezing / Melting

FreezingFreezing: Energy : Energy decreases enough decreases enough so that particles so that particles slow down to slow down to create an ordered, create an ordered, attractive, definite attractive, definite shapeshape

MeltingMelting: an : an increase in energy increase in energy enables particles enables particles to flow around to flow around each othereach other

Evaporation / Evaporation / SublimationSublimation

EvaporationEvaporation: vaporization occurs at : vaporization occurs at the surface of the liquid the surface of the liquid without without boilingboiling

SublimationSublimation: Direct conversion: Direct conversion

from a solid to a gasfrom a solid to a gas

Heating Curve… Why?Heating Curve… Why?

Particles Speeding Up

Particles Speeding Up

Particles Speeding Up

Particle

s Sp

read

ing

Ou

t

Particle

s Sp

read

ing

Ou

t

Solid

Solid + Liquid

Liquid

Liquid + Gas

Solid

Gas

Cooling Curve

Heating Curve… Why?Heating Curve… Why?

Solid