Chemical Reactions
By Chini Lahoti
Physical Change
How does it occur?
Change that occurs without changing the chemical composition
Evidence
- Liquefaction
- Solidification
- Evaporation
- Condensation
- Sublimation
Examples
Ice Melting: When an ice melts, it is still made of the same components- H2O.
Shredding Paper: When the paper tears up, you can't make it a whole paper again, but the components are still the same for the paper.
Chemical Change
How does it occur?
Change that occurs that changes the chemical composition
Evidence
- Color change
- Heat
- New Smell
- Irreversible
- Bubbles
Examples
Oxidation: When oxygen combines with a metal the chemical components change leaving proof in rust.
Baking: When you put the cake in the oven to cook, you're giving it thermal energy mixing all the different ingredients to have one outcome that's irreversible.
Vocab
Exothermic
Releasing of heat
Endothermic
Absorbing of heat
Precipitate
The leftover from a solution that didn't dissolve