How many elements in?

Answer 1

The letters represent elements, the numbers represent the quantity of each element within the compound. I believe it should read 5H2SO4 meaning there are five molecules of the compound H2SO4 (which happens to be sulfuric acid). In this solution there are three different elements:

Hydrogen (H)

Sulfur (S)

Oxygen (O)

In each molecule of H2SO4 there are two Hydrogen atoms, one Sulfur atom, and four Oxygen atoms. In the complete sample, five molecules of H2SO4, there are ten Hydrogen atoms, five Sulfur atoms, and twenty Oxygen atoms.