When a physical change occurs, it may look, act, or feel different, but it is still the same thing. There is no new matter created.
A change of matter in size, shape, or a state without any change in identity.
2. Physical Change in Your Daily Life. 日常生活中的物理变化。
↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓
3. What is Chemical change化学变化 huà xué biàn huà
Achemical change is a change in which something new is formed (irreversible). The starting materials change into anentirely different substance or substances. This new substance has a different chemical composition than the starting materials.
Chemical change may:
a. Release light
c. Give off or take in heat
e. Change smell(Odor)
b. Release gases(Bubbles)
d. Change color
f. Make a precipitation (The mixture of two liquids makes a solid )
4. Law of conservation of mass能量守恒定律néng liàng shǒu héng dìng lǜ
matter can be neither created nor destroyed. In other words, the mass of an object or collection of objects never changes, no matter how the parts are rearranged.
----------------------------------------------------------------Homework: Physical Change Questions: 1. Use your own words to describe what Physical Change is.
2. Give me three examples of physical change in your daily life.
Chemical Change Questions :
1. Why adding baking soda into vinegar is a chemical change?
2. Name another three chemical change that produce gas.
3. Name another three chemical change that have color change.