Question

The highest number of helium atoms is in

• A. 4 mol of helium
• B. 4u of helium
• C. 4g of helium
• D. 2.271098L of helium at STP

Answer 1

Answer: (A)

4 mol of helium

Answer 2

1. 4 u of helium corresponds to one atom of helium (atomic mass unit).
2. 4 g of helium corresponds to 1 mole, which is $6.022 \times 10^{23}$ atoms.
3. At STP, 1 mole of helium occupies 22.4 L. Hence, 2.271098 L corresponds to approximately 0.1 mol, or $6.022 \times 10^{22}$ atoms.
4. 4 moles of helium correspond to $4 \times 6.022 \times 10^{23}$, the highest number of atoms.