INTRODUCTION TO CHEMISTRY

Matter

Science 10 Modified

WHAT IS MATTER?

Matter: anything that takes up space (volume) and has a mass.

PROPERTIES OF MATTER

Physical Property

a property that you can observe

without changing one kind of matter

into something new.

Examples:DensitiesMelting pointsBoiling pointsFreezing pointsColour OdourDuctilityBrittleness

Chemical Property

a property that you can observe

when one kind of matter is

converted into a different kind of

matter.

Examples:Reactivity with

water/air/acidsCombustibilityToxicity

STATES OF MATTER

Soliddefinite shapemolecules close

togetherfirm formationlittle molecular

movement,

Liquidindefinite shapemolecules further

apart than solidsmore molecular

movement

Pressure and temperature influence it.

Gasindefinite shape

and formationMolecules are far

apartThe most molecular

movementconstant motion

Easily affected by temperature and pressure

Solid Liquid Gas

Melt Evaporate

CondenseFreeze

TYPES OF CHANGE:

Physical change: a change that occurs when no new

substance is formed.Properties such as size, shape, colour or

state may change (eg. Boiling water) The reverse is possible.

Chemical change: new substances (with new properties)

are formed from 2 or more different elements. (eg. Rusting of iron)

The reverse is not possible.

CHEMICAL REACTIONS (CHANGE)

When one or more substances are changed into new substances.

Reactants- stuff you start with

Products- what you make

NEW PROPERTIES

Not easily reversed

INDICATIONS OF A CHEMICAL REACTION

Energy absorbed or released – we see this by a temperature change Energy absorbed = temperature increase Energy released = temperature decrease

Permanent color change

Gas produced

Precipitate- solid that separates from solution

Not easily reversed

THERE IS ALWAYS A NEW SUBSTANCE!

CLASSIFICATION OF MATTER

CLASSIFICATION OF MATTER

Pure substance: contains one type of particle. Ex. Elements & compounds

Mixture: contains two or more types of particles intermingling, no chemical bonding.Ex. Homogeneous & Heterogeneous

mixtures

PURE SUBSTANCE OR MIXTURE?

Composed of two or more different atoms

Can be broken down by chemical methods and each part will have different properties

Ex: water (H2O), 2 atoms of hydrogen, I atom of oxygen)salt (NaCl), 1 atom of sodium, 1 atom of chlorine

An element is a substance made up of only one kind of atom

The periodic table arranges elements according to their properties

MIXTURES Heterogeneous mixtures are not

uniform in composition. You will see different layers

Ex: sand and salt oil & water

Homogeneous Mixtures

Appear to be one substance

May be solutions (something dissolved)

WHICH IS IT?

ElementCompoundMixture