Matteranything with mass and volume

Pure Substancescan not be separated by physical means

Mixturescan be separated by physical means

Elementscan not be broken down

chemically or physically – only by nuclear means

Compoundscan be broken down

chemically but not physically

HeterogeneousDon’t look the same

throughout

HomogenousLook the same throughout

Suspension

ColloidSolution

DiatomicIf by itself, only exists as 2 atom moleculesH2, N2, O2, F2, Cl2, Br2, I2

Other elements

Ex: mud water, pizzaLarge particlesPositive Tyndall Effect

Ex: milk, jelloMedium particlesPositive Tyndall Effect

Ex: salt watersmall particlesNegative Tyndall Effect

Tyndall Effect – the scattering of light off of large enough particles.

Element vs. Compound

• Element: a substance that cannot be broken down physically or chemically.

ex: Au, C, O2

• Compound: a substance made of two or more different elements bonded chemically.

ex: NaCl, CO2, H2O

Atom vs. Molecule

• Atom: the smallest unit of an element that retains its properties.

ex: Au, C

• Molecule: a chemically bonded collection of two or more atoms.

ex: NaCl, CO2, H2

Chemical Formula

• Formula indicating the types and number of each element in a compound.

• Ex: CO2 indicates that one carbon atom is bonded to two oxygen atoms to form one molecule of carbon dioxide.

Are the following pure or mixtures?How many different substances are there?

Are they elements or compounds?How many molecules and how many atoms?

• H2O

• F2

• KMnO4

• Ca(OH)2

• 2 Na

• 3 CO2 + 6 Si + 2 H2O

• 5 Al2(SO4)3

Are the following pure or mixtures?How many different substances are there?

Are they elements or compounds?How many molecules and how many atoms?