WHY DOES IT MATTER ? Objectives: Define and give examples of 3 states of matter Distinguish between pure substances and mixtures Define terms related to matter

What is Matter? Anything that has mass and volume (occupies space) Composed of atoms Exists in three states on earth Solid Liquid Gas Exists in fourth state in space Plasma

Solids Definite shape Definite Volume Particles tightly packed and only vibrate

Liquids Definite volume No defined shape Particles have bigger spaces Particles can move past one another

Gases No fixed volume No fixed shape Particles have lots of space between them Particles can move freely

Substances and Mixtures Pure Substance: a particular kind of matter with a definite, fixed composition elements compounds Mixture: a combination of two or more pure substances homogenous heterogeneous

Heterogeneous mixtures (suspensions + mechanical mixtures) Matter Pure substances Mixtures Elements Compounds Heterogeneous mixtures (suspensions + mechanical mixtures) Homogenous (Solutions )

Types of Mixtures Heterogeneous mixtures (two or more parts are visible) oil and vinegar (suspension) Granola (mechanical mixture) Green salad (mechanical mixture) Homogeneous mixtures (appear to be one substance) salt water kool aid metal alloy

Separating Mixtures Filtration Do NOT cause chemical changes Heterogeneous Mixtures sand and water

Separating Mixtures Distillation: Homogeneous Mixtures solutions

Separating Mixtures Chromatography Homogeneous Mixtures solutions (coloured solid in liquid)

Separating Mixtures Recrystallization Homogeneous Mixtures where a solid is the solute

Pure Substances Elements Compound any substances that can not be safely broken down into simpler substances Compound made up of two or more different atoms can be chemically separated

Elements ~111 presently known elements At room temperature: Figure 3.3 – distribution of elements in the

Elements Names of the elements Greek Latin Location where discovered

Elements Arranged in the Periodic Table (inside front cover) Symbols Some symbols are Latin/Greek name (Table 3.4)

Elements Classification Metal Nonmetal Metalloid See Table 3.5

Elements Metals: Usually solid at room temperature High luster Malleable Usually don’t combine with each other

Elements Nonmetals: Solids ( ); Liquid ( ); Gases (all others) Poor conductors Low melting point; Will combine Some found uncombined in nature

Elements Metalloids Have properties of Some used for semiconductors in electronics

Compounds Two or more elements New properties Can be chemically separated

Compounds Molecular Held together with Molecule: Water is an example

Compounds Ionic Ion: Cation – Anion – Held together by ionic bond –

Compounds Diatomic Molecules Always only 2 atoms 7 naturally occurring

Chemical Formulas Abbreviations for compounds Sodium Chloride (NaCl)

Chemical Formulas Subscript indicates # of atoms present H2O has 2 Hydrogen atoms and 1 Oxygen atom NaOH has

Chemical Formulas Parentheses are used to show when a compound contains more than one group of atoms that occurs as a unit

Chemical Formulas Show only number and kind of atom Do not show arrangement of the atoms or how chemically bonded