Signs of a chemical change

By Lauren Johnson Period 1

Chemical changes

A chemical change occurs when a substance changes and it cannot be separated or reversed back to what it was before the change such as: Burning, Rusting, Exploding, and sometimes baking or cooking something such as cake can change it chemically

formation of a precipitate

a precipitate is the formation of a gooey solid such as slime or cheese.

Color change

sometimes when a chemical change occurs the color will change



Example: in a iodine clock the liquid will change from a transparent color to dark purple.

Temperature change

When two substances combine they can get hotter or colder after they chemically change

production of a gas

when two substances combine such as baking soda and vinegar they create a gas and some foamy bubbles

Burning and exploding

burning and exploding an object or substance creates another object called ash and also creates a gas called smoke and produces sound, light, and heat energy

Chemical change is not:

•Freezing

•Melting

•Evaporating

•Condensing

•Mixing

These changes are all physical changes, not chemical.