What is a physical change? What is a chemical change? 10/6/2014 What is a physical change? What is a chemical change?

PARENT TEACHER CONFERENCE LETTER DUE FRIDAY Today’s PLANNER PARENT TEACHER CONFERENCE LETTER DUE FRIDAY

Today’s Goal I can distinguish between physical and chemical changes.

Today’s Plan Physical & Chemical Changes Notes Review Lab Physical & Chemical Changes Practice Demonstrations

PHYSICAL AND CHEMICAL CHANGES

Physical PROPERTY A property that describes a substance without changing the substance Examples: Changes in state Color Odor Malleability Volume Density Ductility Thermal Conductivity Solubility Mass

A change in a substance that does not change what the substance is. Physical CHANGE A change in a substance that does not change what the substance is.

EVIDENCE OF PHYSICAL CHANGE Change in color (NOT extreme) Change in shape **STILL THE SAME SUBSTANCE**

Chemical PROPERTY A property that describes how a substance can change Examples: Ability to rust Reactivity Flammability

Chemical Properties Flammability - The ability to burn Ability to rust - Reacts with oxygen to produce rust Reactivity with vinegar - Reacts with acids to make something new (gases)

Chemical CHANGE A change in a substance that: Results in a new substance Is hard to reverse (change back)

EVIDENCE OF CHEMICAL CHANGE Change in temperature Extreme change in color (white to purple) Bubbles Hard to change back A NEW SUBSTANCE FORMED

1 Glass Breaking 2 Hammering Wood 3 Rusting Bike 6 Bleaching Hair CHEMICAL PHYSICAL PHYSICAL 6 Bleaching Hair 4 Melting Butter 5 Separate Sand & Gravel PHYSICAL CHEMICAL PHYSICAL

7 Frying an egg 8 Squeeze oranges 9 Melting Ice 10 Mix salt and water CHEMICAL PHYSICAL PHYSICAL 10 Mix salt and water 12 Water evaporating 11 Mix oil and water PHYSICAL PHYSICAL PHYSICAL

13 Cutting grass 14 Burning Leaves 15 Fireworks exploding CHEMICAL PHYSICAL CHEMICAL 17 Crushing a can 16 Cutting hair 18 Boiling water PHYSICAL PHYSICAL PHYSICAL

Hydrogen Physical Properties: Chemical Properties: Colorless Flammable Gas at room temp Chemical Properties: Flammable Very reactive

Oxygen Physical Properties: Chemical Properties: Colorless gas Gas at room temp Nonmalleable Nonductile Chemical Properties: Flammable Very reactive

Water (H2O) Physical Properties: Chemical Properties: Colorless when gas Clear liquid & solid Can be solid, liquid, or gas at normal temps Chemical Properties: Nonflammable Nonreactive

Sodium (Na) Physical Properties: Chemical Properties: Soft Silver Metal Malleable Nonductile Nonsoluble Chemical Properties: Reactive with water Reactive with oxygen

Chlorine (Cl) Physical Properties: Chemical Properties: Green Occurs as gas Chemical Properties: Toxic Gas Very reactive

NaCl Physical Properties: Chemical Properties: Solid White Soluble in water Nonmalleable Nonductile Not a good conductor Chemical Properties: Nonflammable Mostly nonreactive