Ion Chemistry Example 1

Follow the full solution, then compare it with the other examples linked below.

easy

Sodium (

Z = 11

) loses one electron. Write the ion formed and its electron configuration.

1
Neutral Na: $1s^2\,2s^2\,2p^6\,3s^1$ (11 electrons).
2
Losing 1 electron: $\text{Na}^+$ with configuration $1s^2\,2s^2\,2p^6$ (10 electrons).
3
This is the same electron configuration as neon (isoelectronic with Ne).

Answer

\text{Na}^+:\; 1s^2\,2s^2\,2p^6

Metals tend to lose electrons to form cations. Sodium loses its single valence electron to achieve the stable noble gas configuration of neon.

About Ion

An atom or group of atoms that has gained or lost one or more electrons, resulting in a net positive charge (cation) or net negative.

An unknown ion has 10 electrons, 8 protons, and 8 neutrons. Identify the element, write the ion symb

Predict the ion formed by each: (a) calcium, (b) fluorine, (c) aluminum.

Aluminum loses 3 electrons. What ion forms, and why is its charge positive?