How is #"chemical change"# differentiated from #"physical change"#?
2 Answers
Physical change: the identity of the substance(s) doesn't change
Chemical change: the substance reacts and forms (a) new substance(s), cannot be changed back easily, heat or energy is often released/absorbed (exothermic vs. endothermic reactions), a precipitate may form
Basically, you KNOW a chemical change has occurred if you do not change the temperature/heat/energy around a substance, and a change still occurs. If you change the heat/temperature/energy around a substance and a change occurs, then it's considered to be a physical change.
Explanation:
Quiz: (answers below)
- Dropping a glass
- Burning toast
- Wood expanding in the summer
- Melting butter for popcorn
- Spoiling food
- Fireworks exploding
- Bleaching your hair
- Cooking an egg
- Cream being whipped
- Mixing lemon powder with water to make lemonade
Note: if this is still unclear, please tell me and I'll try my best to help!
Answers: P, C, P, P, C, C, C, C, P, P
Chemical change is characterized by the formation of new substances, and the making and breaking of chemical bonds.....
Explanation:
Physical changes are largely changes of state, solid to liquid to gas, etc. in which the phase of the substance changes but not its chemical identity.
