1. Understand the Relationship:
* Molar Mass: The molar mass of helium (He) is 4.003 g/mol. This means that one mole of helium weighs 4.003 grams.
2. Set Up the Calculation:
* We'll use the following formula:
* moles = mass (g) / molar mass (g/mol)
3. Plug in the Values:
* mass (g) = 6.45 x 10^10 g (Note: tenth grams means 10^10 grams)
* molar mass (g/mol) = 4.003 g/mol
4. Calculate:
* moles = (6.45 x 10^10 g) / (4.003 g/mol)
* moles ≈ 1.61 x 10^10 mol
Therefore, there are approximately 1.61 x 10^10 moles of helium in 6.45 x 10^10 grams of helium.
