It indicates what elements is composed by and how many atoms of one element are linked to the other.
For example, this is the formula for table salt is:
NaCl
The formula indicates that table salt (sodium chloride) is composed by sodium (Na) and chlorine (Cl) on a 1:1 ratio.
Hope it helped,
BioTeacher101
Answer:
Scientists mostly gain new knowledge through direct observation and applying the scientific method. They would start with a hypothesis and test it, then change it or confirm it. Others would test their confirmation from one point, while the third group would test what the second said. And so on and so forth.
Explanation:
There are two oxygen atoms. The OH is in parentheses with the 2 after it to indicate that there are two OH molecules, each containing on atom of oxygen.