Geologic time periods are divided into segments based on two pieces of information. describe them.

Answer the appearance and disappearance of fossils, and major physical change on the earths surface

Evaporation: this is when warmth from the sun causes water from oceans, lakes, streams, ice and soils to rise into the air and turn into water vapour (gas). water vapour droplets join together to make clouds! condensation: this is when water vapour in the air cools down and turns back into liquid water.