Question

How many helium atoms are there in a helium blimp containing 540 kg of helium?

Answer 1

The answer is 8.13 x 10²⁸ atoms.

First we calculate  the number of moles using the molar mass.

molar mass of helium = 4 g/mol. 

it means that 1 mole of helium atoms weighs 4 gram.

Now we have 540 kg of helium =540000 grams

Number of moles in 540000 grams;

540000 / 4 =135000 mol

Now in one mole there is 6.02 x 10²³ atoms

So, in 135000 mol there is;

135000 x 6.02 x 10²³  = 8.13 x 10²⁸atoms