Total number of electrons present in `48g Mg^(2+)` are :

Options

A. ` 24 N_(A)`
B. ` 2 N_(A)`
C. `20 N_(A)`
D. None of these

Answer

To find the total number of electrons present in 48 g of \( \text{Mg}^{2+} \), we can follow these steps:

### Step 1: Calculate the number of moles of \( \text{Mg}^{2+} \)
We start by using the formula for calculating moles, which is given by:

\[ \text{Number of moles} = \frac{\text{Mass (g)}}{\text{Molar mass (g/mol)}} \]

For magnesium (\( \text{Mg} \)), the molar mass is approximately 24 g/mol. Therefore, for 48 g of \( \text{Mg}^{2+} \):

\[ \text{Number of moles of } \text{Mg}^{2+} = \frac{48 \text{ g}}{24 \text{ g/mol}} = 2 \text{ moles} \]

### Step 2: Determine the number of electrons in \( \text{Mg}^{2+} \)
The atomic number of magnesium (\( \text{Mg} \)) is 12, which means a neutral magnesium atom has 12 electrons. However, since we are dealing with \( \text{Mg}^{2+} \), it has lost 2 electrons. Therefore, the number of electrons in \( \text{Mg}^{2+} \) is:

\[ \text{Electrons in } \text{Mg}^{2+} = 12 - 2 = 10 \text{ electrons} \]

### Step 3: Calculate the total number of electrons in 48 g of \( \text{Mg}^{2+} \)
Now that we know there are 10 electrons in one mole of \( \text{Mg}^{2+} \), we can find the total number of electrons in 2 moles:

\[ \text{Total electrons} = \text{Number of moles} \times \text{Electrons per mole} \]
\[ \text{Total electrons} = 2 \text{ moles} \times 10 \text{ electrons/mole} = 20 \text{ electrons} \]

### Final Answer:
The total number of electrons present in 48 g of \( \text{Mg}^{2+} \) is **20 electrons**.

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