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

• A. 2 moles
• B. 9 moles
• C. 4 moles
• D. 0.25 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: \(\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}\).
3. Substitute the given values into the formula: \(\text{moles} = \frac{36\ \text{g}}{9\ \text{g/mol}}\).
4. Perform the division to find the number of moles (do not calculate the final value here, just set up the expression).
5. Interpret the result as the amount of substance in moles present in 36 g of Be.