Question

Which is the noble gas notation for chlorine?

Answer 1

• [Ne] 3s² 3p⁵

Step-by-step explanation:

Chlorine's atomic number is 17.

That means that it has 17 protons and 17 electrons.

Then, you have to write the electron configuration for the 17 electrons.

The noble gas notation is a short notation that uses the previous noble gas symbol (closed in brackets) and adds the new electrons, filling the orbitals in increasing order of energy, which you can remember using Aufbau rules.

Then:

• number of electrons: 17
• Previous noble gas: neon, which has 10 electrons.
• Then, you use [Ne] and add 17 - 10 = 7 more electrons.
• Since, the electron configuration of neon is 1 s² 2s² 2p⁶, the seven electrons that you have to add will occupy the orbitals 3s and 3p.

Result: [Ne] 3s² 3p⁵ ← answer