What describes a chemical change?

A chemical change is a type of change that forms new substances .

Explanation:

The five conditions of chemical change are : color change, formation of a precipitate, formation of a gas, odor change and temperature change.

Eg: Burning of coal, Rusting of iron, etc.

answer: i'm not sure which is which for i get confused on it all the time but i can tell you that the answer lies with the convex and concave devices. i hope this you. have a good day and best of luck to you!

explanation:

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.