4c.

Question 1

Water is a compound and has the chemical symbol: (H2O)

In chemical symbols of compounds like water (H2O)…
* What do the letters tell you?
* What do the numbers tell you?

Answer 1

• The letters tell you the elements the compound is made of.
  ( H=Hydrogen, O=Oxygen)
• The numbers tell you how many atoms of each element there are.
  (ex. H2 has 2 atoms of Hydrogen)