1. 什么是物理变化(Physical Change)?

 

• 物质的外面的变化；还有原来的特征(te zheng)

• when the appearance of a substance changes, but what it is made of does not change; it still holds on to its properties and characteristics

 

2. 什么是化学变化(Chemical Change)?

 

• 当两个或更多的反应物(fan ying wu)混合(hun he)在一起，产生(chang sheng)了新的物质。

• When two or more reactants are mixed to make a new substance.

 

 - 四个化学变化的特点(4 characteristics of chemical change)

 

     1. 产生气体

       produces a gas

     2. 散发出热，光，和气味

       emission of heat, light, odor

     3. 颜色的改变

       color change

     4. 形成固体

       a solid is formed

      When a reaction has more than one of these things going on, it must be CHEMICAL !!!

 

   Watch this awesome video and do the following assignment: 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Assisgnment (Write on a paper and turn in tomorrow for 5 class bucks !!!)

 

1. Think about one example of physical change in your house, and explain why you think it is physical.

 

2. Think about one example of chemical change in your house, and explain why you think it is chemical.