Physical and Chemical Changes

Physical Changes

Physical changes- A change that affects one or more physical properties of a substance but does not change the chemical identity of the substance.

If you melt a block of ice, you still have H2O at

the end of the change. 

Physical Changes

Any change in size, shape, form, or state where the identity of the matter stays the same

Example:cutting a watermelon into slicestearing up a sheet of papersharpening a pencil

Often easy to reverse with:filtration, magnetism, evaporation, distillation and centrifuge (spinning)

Signs that a physical change is taking place

•Change in Appearance•Change in state of matter•Observed without doing anything•Measured quantity

Key words to look forMeltsEvaporatesBentConductor

Physical Change

Physical Changes

Some common examples of physical changes are: melting, freezing, condensing, breaking, crushing, cutting, and bending.

Chemical Changes

Chemical changes, or chemical reactions, are changes that result

in the production of another substance. 

Chemical Changes

Signs that a chemical change (reaction) is taking place•Bubbles form•Odor released/ forms•Fizzing occurs•Something burns•A gas is released•Heat produced•Light produced•Precipitate (solid) forms•Rusting occurs•A color change occurs

Key words to look forBurningReactsBubblesTarnishesExplodesHeats upSours

Physical or Chemical Change?

Painting WoodPHYSICAL

Physical or Chemical Change?

•Burning Paper

•CHEMICAL

Physical or Chemical Change?

•Digestion of food

•CHEMICAL

Physical or Chemical Change?

•Sugar dissolving in water

•PHYSICAL

Physical or Chemical Change?

•Iron turning red when heated

•PHYSICAL

Physical or Chemical Change?

•Evaporation

•PHYSICAL

Physical or Chemical Change?

•A pond freezing in winter

•PHYSICAL

Physical or Chemical Change?

•Melting ice

•PHYSICAL

Physical or Chemical Change?

•Cutting wire

•PHYSICAL

Physical or Chemical Change?

•Painting fingernails

•PHYSICAL

Physical or Chemical Change?

•Cutting fabric

•PHYSICAL

Physical or Chemical Change?

•Baking muffins

•CHEMICAL

Physical or Chemical Change?

•Shattering glass

•PHYSICAL

Physical or Chemical Change?

•Decomposition of old leaves

•CHEMICAL

Physical or Chemical Change?

•Wrinkling a shirt

•PHYSICAL

Physical or Chemical Change?

•An old nail rusting

•CHEMICAL