The number of atoms in `4.25 g NH_(3)` is approximately:

Options

A. `1xx10^(23)`
B. `1.5xx10^(23)`
C. `2xx10^(23)`
D. `6xx10^(23)`

Explanation

To find the number of atoms in 4.25 g of ammonia (NH₃), we can follow these steps:

### Step 1: Calculate the molar mass of ammonia (NH₃).
The molar mass of NH₃ can be calculated as follows:
- Nitrogen (N) has an atomic mass of approximately 14 g/mol.
- Hydrogen (H) has an atomic mass of approximately 1 g/mol, and there are 3 hydrogen atoms in ammonia.

So, the molar mass of NH₃ is:
\[ \text{Molar mass of NH}_3 = 14 \, \text{g/mol (N)} + 3 \times 1 \, \text{g/mol (H)} = 14 + 3 = 17 \, \text{g/mol} \]

### Step 2: Calculate the number of moles of NH₃ in 4.25 g.
To find the number of moles, we use the formula:
\[ \text{Number of moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \]
Substituting the values:
\[ \text{Number of moles} = \frac{4.25 \, \text{g}}{17 \, \text{g/mol}} \approx 0.25 \, \text{mol} \]

### Step 3: Calculate the number of molecules in 0.25 moles of NH₃.
Using Avogadro's number, which is \(6.022 \times 10^{23}\) molecules/mol:
\[ \text{Number of molecules} = \text{Number of moles} \times \text{Avogadro's number} \]
Substituting the values:
\[ \text{Number of molecules} = 0.25 \, \text{mol} \times 6.022 \times 10^{23} \, \text{molecules/mol} \approx 1.5055 \times 10^{23} \, \text{molecules} \]

### Step 4: Calculate the total number of atoms in the molecules of NH₃.
Each molecule of NH₃ contains 4 atoms (1 nitrogen and 3 hydrogen). Therefore, the total number of atoms is:
\[ \text{Total number of atoms} = \text{Number of molecules} \times \text{Number of atoms per molecule} \]
Substituting the values:
\[ \text{Total number of atoms} = 1.5055 \times 10^{23} \, \text{molecules} \times 4 \, \text{atoms/molecule} \approx 6.022 \times 10^{23} \, \text{atoms} \]

### Conclusion
The number of atoms in 4.25 g of NH₃ is approximately \(6 \times 10^{23}\) atoms.

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