Question

what is the electron configuration of chlorine (cl)?
○ $1s^22s^22p^63s^23p^3$
○ $1s^22s^22p^63s^23p^5$
○ $1s^22s^22p^63s^24s^23p^3$
○ $1s^22s^22p^63s^23p^23d^3$

Explanation:

Chlorine (Cl) has an atomic number of 17, meaning it has 17 electrons. The electron configuration follows the Aufbau principle, filling orbitals in order of increasing energy: 1s, 2s, 2p, 3s, 3p, etc.

• The first two electrons go to 1s: \(1s^2\).
• Next two to 2s: \(2s^2\).
• Then six to 2p (since p orbitals can hold 6 electrons): \(2p^6\).
• Next two to 3s: \(3s^2\).
• Remaining \(17 - 2 - 2 - 6 - 2 = 5\) electrons go to 3p: \(3p^5\).

So the electron configuration is \(1s^22s^22p^63s^23p^5\).

Answer:

B. \(1s^22s^22p^63s^23p^5\)