How many moles of beryllium atoms are present in 36 g of Be? (Atomic mass of Be = 9 g/mol)

• A. 2 moles
• B. 0.25 moles
• C. 4 moles
• D. 9 moles

Answer: (C)

Verified step by step guidance

1. Identify the given information: mass of beryllium (Be) is 36 g, and the atomic mass of Be is 9 g/mol.
2. Recall the formula to calculate moles from mass: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\).
3. Substitute the given values into the formula: \(\text{moles of Be} = \frac{36\ \text{g}}{9\ \text{g/mol}}\).
4. Perform the division to find the number of moles (do not calculate the final number here, just set up the expression).
5. Interpret the result as the amount of beryllium atoms in moles present in the 36 g sample.