The geologic time scale is organized into four major divisions. List these divisions and describe how they are determined.

The geologic time scale is divided into eons, eras, periods, epochs and ages with eons being the longest time divisions and ages the shortest. The history of the earth is broken up into a hierarchical set of divisions for describing geologic time. As increasingly smaller units of time, the generally accepted divisions are eon, era, period, epoch, age.

Explanation:

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

the diploid number of chromosomes is sometimes represented by the symbol 2n. for the fruit fly, the diploid number is 8, which can be written as 2n = 8, where n represents twice the number of chromosomes in a sperm or egg cell.