# How many helium atoms are in a helium blimp containing 494 kg of helium?

##### 1 Answer

Jul 23, 2016

#### Explanation:

**Step 1:** calculate how the number of moles using the molar mass.

The molar mass of helium =

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

In this case you have

**Step 2** : calculate the number of atoms using Avogadro's constant.

Avogadro's constant states that there are

How many atoms are in 123.500 moles?