What is the electron configuration of chlorine [tex]\(( Cl )\)[/tex]?

A. [tex]\(1s^2 \ 2s^2 \ 2p^6 \ 3s^2 \ 3p^3\)[/tex]
B. [tex]\(1s^2 \ 2s^2 \ 2p^6 \ 3s^2 \ 3p^5\)[/tex]
C. [tex]\(1s^2 \ 2s^2 \ 2p^6 \ 3s^2 \ 4s^2 \ 3p^3\)[/tex]
D. [tex]\(1s^2 \ 2s^2 \ 2p^6 \ 3s^2 \ 3p^2 \ 3d^3\)[/tex]



Answer :

To determine the electron configuration of chlorine (Cl), follow these steps:

1. Determine the number of electrons in chlorine: Chlorine has an atomic number of 17, indicating it has 17 electrons in its neutral state.

2. Fill the electron shells according to the Aufbau principle: First, we fill the lower energy orbitals before filling the higher energy orbitals. The order of filling is:
- 1s
- 2s
- 2p
- 3s
- 3p

3. Distribute the 17 electrons:
- 1s orbital can hold up to 2 electrons.
- 2s orbital can also hold up to 2 electrons.
- 2p orbital can hold up to 6 electrons.
- 3s orbital can hold up to 2 electrons.
- 3p orbital can hold up to 6 electrons.

Let's fill the electrons step-by-step:
- 1s: 2 electrons
[tex]\( \text{1s}^2 \)[/tex]
- 2s: 2 electrons
[tex]\( \text{1s}^2 \text{2s}^2 \)[/tex]
- 2p: 6 electrons
[tex]\( \text{1s}^2 \text{2s}^2 \text{2p}^6 \)[/tex]
- 3s: 2 electrons
[tex]\( \text{1s}^2 \text{2s}^2 \text{2p}^6 \text{3s}^2 \)[/tex]
- Remaining electrons (17 - 2 - 2 - 6 - 2 = 5) will go into the 3p orbital.
[tex]\( \text{1s}^2 \text{2s}^2 \text{2p}^6 \text{3s}^2 \text{3p}^5 \)[/tex]

4. Compare with the given options:

- Option 1: [tex]\(1 s^2 2 s^2 2 p^6 3 s^2 3 p^3\)[/tex]
- Option 2: [tex]\(1 s^2 2 s^2 2 p^6 3 s^2 3 p^5\)[/tex]
- Option 3: [tex]\(1 s^2 2 s^2 2 p^6 3 s^2 4 s^2 3 p^3\)[/tex]
- Option 4: [tex]\(1 s^2 2 s^2 2 p^6 3 s^2 3 p^2 3 d^3\)[/tex]

The correct electron configuration matches option 2:
[tex]\( \text{1s}^2 \text{2s}^2 \text{2p}^6 \text{3s}^2 \text{3p}^5 \)[/tex].

Thus, the correct answer is option 2, corresponding to the numerical result:
[tex]\[ \boxed{1} \][/tex]