The number of atoms in 0.004g of magnesium will be

Options

A. `4 xx 10^(20)`
B. `8 xx 10^(20)`
C. `10^(20)`
D. `6.02 xx 10^(20)`

Explanation

To find the number of atoms in 0.004 g of magnesium, we can follow these steps:

### Step 1: Determine the molar mass of magnesium.
The molar mass of magnesium (Mg) is approximately 24 g/mol.

### Step 2: Calculate the number of moles of magnesium in 0.004 g.
To find the number of moles, we use the formula:

\[ \text{Number of moles} = \frac{\text{Given mass}}{\text{Molar mass}} \]

Substituting the values:

\[ \text{Number of moles} = \frac{0.004 \text{ g}}{24 \text{ g/mol}} = \frac{0.004}{24} \approx 1.6667 \times 10^{-4} \text{ moles} \]

### Step 3: Use Avogadro's number to find the number of atoms.
Avogadro's number is \(6.022 \times 10^{23}\) atoms/mol. To find the number of atoms, we multiply the number of moles by Avogadro's number:

\[ \text{Number of atoms} = \text{Number of moles} \times \text{Avogadro's number} \]

Substituting the values:

\[ \text{Number of atoms} = 1.6667 \times 10^{-4} \text{ moles} \times 6.022 \times 10^{23} \text{ atoms/mol} \]

Calculating this gives:

\[ \text{Number of atoms} \approx 1.004 \times 10^{20} \text{ atoms} \]

### Final Answer:
The number of atoms in 0.004 g of magnesium is approximately \(1.004 \times 10^{20}\) atoms.

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