Mass of one atom of an element is 7.64×`10^(−24)`g. This is equal to :

Options

A. 4.59u
B. 5.48u
C. 56u
D. None of these

Explanation

To solve the problem, we need to find the mass of one mole of atoms (also known as the molar mass) given the mass of one atom of the element.

### Step-by-Step Solution:

1. **Identify the mass of one atom**:
The mass of one atom of the element is given as:
\[ \text{Mass of one atom} = 7.64 \times 10^{-24} \text{ g} \]

2. **Use Avogadro's number**:
Avogadro's number (\(N_A\)) is the number of atoms in one mole, which is approximately:
\[ N_A = 6.02 \times 10^{23} \text{ atoms/mole} \]

3. **Calculate the mass of one mole of atoms**:
The mass of one mole of atoms can be calculated using the formula:
\[ \text{Mass of one mole} = N_A \times \text{Mass of one atom} \]
Substituting the values:
\[ \text{Mass of one mole} = (6.02 \times 10^{23}) \times (7.64 \times 10^{-24}) \]

4. **Perform the multiplication**:
\[ \text{Mass of one mole} = 6.02 \times 7.64 \times 10^{23 - 24} \]
\[ = 6.02 \times 7.64 \times 10^{-1} \]
\[ = 45.96 \times 10^{-1} \text{ g} \]
\[ = 4.596 \text{ g} \]

5. **Round the result**:
Rounding to three significant figures, we get:
\[ \text{Mass of one mole} \approx 4.59 \text{ g} \]

### Final Answer:
The mass of one mole of the element is approximately **4.59 g**.

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