Question

1 gram of hydrogen contains 6x10^23 atoms
Then 4 grams of He contains
1) 6 x 10^23 atoms 2) 12 x 10^23 atoms
3) 24 x 10^23 atoms 4) 1.5 x 10^23 atoms​

Answer 1

Answer:

4) 1.5*1023 atoms

Explanation:

Since atomic weight of H is 1 u, 1 g means 1 mole.

1 mole of Hydrogen contains 6*1023 atoms.

No of moles in 1 g of He = 1/4 = 0.25 mol

No of atoms in one mole = 6*1023

No of atoms in 0.25 moles = 0.25*6*1023 = 1.5*1023 atoms

Hope it helps  : )