Question

Write the electronic configuration of chlorine.

Hint:

Chlorine has 7 valence electrons, making it highly reactive as it seeks to gain one more electron to achieve a stable octet configuration, similar to the noble gas Argon.

Answer 1

The atomic number of chlorine (Cl) is 17, which means a neutral chlorine atom has 17 protons and 17 electrons. These electrons are arranged in shells (energy levels) around the nucleus according to the rule that the K shell can hold up to 2 electrons, the L shell up to 8, the M shell up to 18, and so on. The electronic configuration of chlorine is:
K shell (n=1): 2 electrons
L shell (n=2): 8 electrons
M shell (n=3): 7 electrons
So, the configuration is written as 2, 8, 7.