Question

What is the electron configuration of an isolated Cl atom? Express your answer in condensed form in order of increasing orbital energy as a string without blank space between orbitals. For example, [He]2s22p2 should be entered as [He]2s^22p^2.

Answer 1

Answer: $[Ne]3s^23p^5$

Explanation:

Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.

The electrons are filled according to Afbau's rule in order of increasing energies .  Chlorine atom has 17 atomic number of 17 and has 17 electrons. The nearest noble gas is Neon with 10 electrons and thus the electronic configuration in terms of noble gas is:

$Cl:17:[Ne]3s^23p^5$