Answer:
There are 2 atoms of hydrogen in 1 molecule of water (H2O).
To find the number of atoms of hydrogen in 1 mole of water, we need to multiply the number of hydrogen atoms per molecule by Avogadro's number, which is approximately 6.02 x 10^23.
So, 1 mole of water contains:
2 atoms of hydrogen per molecule x Avogadro's number
= 2 x 6.02 x 10^23
= 1.204 x 10^24 atoms of hydrogen.