GCSE Chemistry 1: What does it mean that 32 grams of O2 contain the same number of molecules as 18 grams of H2O?

Question

What does it mean that 32 grams of O2 contain the same number of molecules as 18 grams of H2O?

daavide · Accepted Answer

It means that both samples contain Avogadro's number of molecules, which is approximately 6.02 × 10^23 particles.

What does it mean that 32 grams of O2 contain the same number of molecules as 18 grams of H2O?