1 Clouds are formed when millions of drops of water become suspended in the air. Which of the following is a step in the process of cloud formation?
A Expansion of cold air
B Formation of carbon dioxide
C Condensation of water vapor
D Breakdown of atmospheric ozone

C Condensation of water vapor

Explanation:

One of the components of the atmosphere is water vapour. Water vapour is always present in air.

This water vapour may combine with particles of dust and smoke and condense around them to form clouds.

As more water vapour condenses and coalesces, the clouds become thicker and precipitation eventually follows.

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a