Explanation:
one gram of hydrogen contains one mole of hydrogen as its atomic weight is 1. One mole is 6.02x10^23 atoms. But, hydrogen is diatomic, meaning its atoms are found in pairs so, the amount of molecules would be 3.01x10^23.
so , 1000 grams = 3.01 x 10 ^ 23 x 1000
= 3.01 x 10 ^ 26
