Define:

Photochemical reaction

Define:

Electrochemical reaction. Give one example of each.

Complete the following statements by using proper words:

The temperature at which a solid changes into a liquid is called _____.

Complete the following statement by using proper word:

The process of a solid changing directly into a gas is called _____.

Complete the following statements by using proper words:

A change which alters the composition of a substance is known as a  _____ change.

Complete the following statement by using the proper word:

Substances that influence the rate of a chemical reaction by improving the efficiency of the catalyst are called _____ catalyst. (Positive/ Negative)