Before modern chemistry, how did people know what atoms the different substances were made of? For example H2O. How did they know water has two hydrogen atoms and an oxygenatom?

Before modern chemistry, how did people know what atoms the different

1.	Before modern chemistry, how did people know what atoms the different substances were made of? For example H2O. How did they know water has two hydrogen atoms and an oxygenatom?
Answer» TION:To find out what WATER is made of, it HELPS to look at its chemical formula, which is H2O. This BASICALLY tells us that the water molecule is composed of two elements: hydrogen and oxygen or, more precisely, two hydrogen atoms (H2) and one oxygen ATOM (O