Think about how the geologic time scale was created and how it is divided. Then answer the following questions. HELP ILL GIVE BRAINLEIST!!

How did scientists form the geologic time scale?
How is this scale organized?
What processes changed the Earth's environment during Precambrian time?

In the 1800s, many americans believed in the policy of manifest destiny. what did this mean? the nation’s mission was to expand to the pacific ocean. the nation should stay away from involvement with foreign countries. the nation should latin american countries achieve independence. the nation’s mission was to expand into latin america.