Answer to Question #125989 in Chemistry for xio

Question

Identify a neutral atom, a negatively charged atom (anion) and a positively charged atom (cation) with the following electron configuration:

1s2 2s2 2p6 3s2 3p6

Neutral atom:

Anion:

Cation:

Answer 1

Solution:

The number of electrons in a neutral atom is equal to the number of protons.

In turn, the number of protons in the nucleus of the atom is equal to the atomic number (Z).

The electron configuration of a neutral atom (1s²2s²2p⁶3s²3p⁶) corresponds to 18 electrons.

Therefore,

Neutral atom: Argon (Ar)

When an atom gains electron(s) it becomes negatively charged and is called an anion. 

Suitable anion: chloride ion (Cl^-) or sulfide ion (S^2-) or  phosphide ion (P^3-).

When an atom loses electron(s) it becomes positively charged and is called a cation.

Suitable cation: calcium ion (Ca²⁺) or potassium ion (K⁺) or scandium ion (Sc³⁺).