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.