ANSWER
The number of moles of helium is 4.0 mol
EXPLANATION
Given information
[tex]\text{ The number of helium atoms is 2.4}\times10^{24}\text{ atoms}[/tex]
To find the number of moles of helium, follow the steps below
Step 1: Write the formula for calculating the number of moles
[tex]\text{ Mole }\frac{\text{ number of atoms}}{\text{ Avogadro's number}}[/tex][tex]\text{ Recall, that Avogadro's number is 6.022}\times10^{23}[/tex]
Step 2: Substitute the given data into the formula in step 1
[tex]\begin{gathered} \text{ Mole = }\frac{\text{ number of atoms}}{\text{ Avogadro's number}} \\ \text{ } \\ \text{ Mole = }\frac{2.4\times10^{24}}{6.022\times10^{23}} \\ \\ \text{ Mole = }\frac{2.4}{6.022}\times10^{24-23} \\ \\ \text{ Mole = 0.3985}\times10 \\ \text{ Mole = 3.985} \\ Mole\approx4.0\text{ mol} \end{gathered}[/tex]
Hence, the number of moles of helium is 4.0 mol