The number of mole in 48 g He are _______? 

The correct answer is 12.

Explanation:

Number of grams of Helium (He) = 48 gm

Molecular mass is the sum of total protons and neutrons.

The molecular mass of Helium = 2 × 2 = 4

Now multiply the mass by the number of elements we get

⇒  4 × 1 = 4

One mole is equal to the total mass of the molecule.

We know one mole is equal to 4 gm of a Glucose molecule.

Now the number of moles in 48 gm of Helium is

⇒ (n) = 48/4

⇒ n = 12 moles

The number of moles in 48 gm is 12 moles.