How many moles of hydrogen gas contian the same numbers of atoms as there are in 16g of helium?

The atomic mass of helium is 4, so there are 4 moles of helium in 16g. Since we want the same number of atoms, we want 4 moles of H, which is 2 moles of H2. (If you really meant same number of molecules of hydrogen as there are atoms of helium, the answer is 4 instead.)