What is a chemical change? and what is a physical change?

In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition.

A chemical change is a change where something new can be formed and normally can not be changed back. Examples of a chemical change are precipitates being formed, gases being formed, quick temperature change rust, bubbling, foaming, burning, etc. A physical change is a change where nothing new is formed and normally can be changed back. For example you painted a wooden block red. If you want, you can always change the color again. Nothing chemically or permanantly happened to it. More examples of a physical change are; color change, change of state, luster, shape, size, hardeness, etc.      

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jjj89t'ji; it hink the answer is your mom is not si

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )