The outer electronic configuration of Mg,K and Ca respectively are

Options

A. `3s^2.4s^1,4s^2`
B. `2s^2,4s^2,4s^2`
C. `3s^2,4s^2,4s^1`
D. `3s^2,4s^2,4s^2`

Answer

To determine the outer electronic configurations of Magnesium (Mg), Potassium (K), and Calcium (Ca), we will follow these steps:

### Step 1: Identify the Period and Group of Each Element
- **Magnesium (Mg)**: It is in the 3rd period and belongs to Group 2.
- **Potassium (K)**: It is in the 4th period and belongs to Group 1.
- **Calcium (Ca)**: It is in the 4th period and belongs to Group 2.

### Step 2: Determine the Valence Electrons
- Elements in Group 2 have **2 valence electrons**.
- Elements in Group 1 have **1 valence electron**.

### Step 3: Write the Outer Electronic Configuration
- For **Magnesium (Mg)**:
- Since it is in the 3rd period and has 2 valence electrons, the outer electronic configuration is **3s²**.

- For **Potassium (K)**:
- Since it is in the 4th period and has 1 valence electron, the outer electronic configuration is **4s¹**.

- For **Calcium (Ca)**:
- Since it is in the 4th period and has 2 valence electrons, the outer electronic configuration is **4s²**.

### Final Answer
- The outer electronic configurations are:
- Magnesium (Mg): **3s²**
- Potassium (K): **4s¹**
- Calcium (Ca): **4s²**

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