Number of unpaired electrons in `1s^(2),2s^(2)2p^(3)` is

Options

A. 2
B. 0
C. 3
D. 1

Explanation

To determine the number of unpaired electrons in the electronic configuration `1s² 2s² 2p³`, we will follow these steps:

### Step 1: Identify the Electron Configuration
The given electron configuration is `1s² 2s² 2p³`. This means:
- The `1s` subshell has 2 electrons.
- The `2s` subshell has 2 electrons.
- The `2p` subshell has 3 electrons.

### Step 2: Determine the Filling of Electrons
- The `1s` subshell can hold a maximum of 2 electrons, and since it has 2 electrons, it is fully filled.
- The `2s` subshell can also hold a maximum of 2 electrons, and since it has 2 electrons, it is also fully filled.
- The `2p` subshell can hold a maximum of 6 electrons, but in this case, it has only 3 electrons.

### Step 3: Analyze the 2p Subshell
In the `2p` subshell, the electrons are distributed among the three available p orbitals (2p_x, 2p_y, and 2p_z). According to Hund's rule, electrons will occupy separate orbitals first before pairing up.

- Since there are 3 electrons in the `2p` subshell, they will occupy the three p orbitals singly:
- 2p_x: 1 electron
- 2p_y: 1 electron
- 2p_z: 1 electron

### Step 4: Count the Unpaired Electrons
All three electrons in the `2p` subshell are unpaired because they occupy separate orbitals.

### Conclusion
Thus, the total number of unpaired electrons in the configuration `1s² 2s² 2p³` is **3**.

### Final Answer
The number of unpaired electrons is **3**.

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