What is the terms definition file catpyxnece

a collection of related data or program records stored on some input/output or auxiliary storage medium: This program's main purpose is to update the customer master file.

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.