Number of atoms in `558.5` ` g ` `Fe (at.wt.55.85)` is:

Options

A. twice that in 60 g carbon
B. `6.023 xx 10^(22)`
C. half that in 8 g He
D. `558.5xx 6.023 xx 10^(23)`

Explanation

To find the number of atoms in 558.5 g of iron (Fe) with an atomic weight of 55.85 g/mol, we can follow these steps:

### Step 1: Calculate the number of moles of Fe
To find the number of moles, we use the formula:

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

Given:
- Weight of Fe = 558.5 g
- Molar mass of Fe = 55.85 g/mol

Substituting the values:

\[ \text{Number of moles of Fe} = \frac{558.5 \, \text{g}}{55.85 \, \text{g/mol}} \approx 10 \, \text{moles} \]

### Step 2: Calculate the number of atoms
To find the number of atoms, we use Avogadro's number (Na), which is approximately \(6.022 \times 10^{23}\) atoms/mol.

The formula to calculate the number of atoms is:

\[ \text{Number of atoms} = \text{Number of moles} \times N_a \]

Substituting the values:

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

Calculating this gives:

\[ \text{Number of atoms} = 6.022 \times 10^{24} \, \text{atoms} \]

### Final Answer
The number of atoms in 558.5 g of Fe is \(6.022 \times 10^{24}\) atoms.

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