Question

Write the symbol for oxide ion

Answer 1

Definition of ion

An ion is a positively or negatively charged atom or group or atom. For Ex: Sodium-ion, Magnesium ion,Chloride ion,oxide ion etc. There are two types of ions:

Cation: A positively charged ion is known as a cation. A cation is formed by the loss of one or more electrons by an atom

Anion: A negatively charged ion is known as an anion. An anion is formed by the gain of one or more electrons by an atom

Explanation

Oxygen :

• Oxygen is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with compounds
• It is a chemical element that constitutes 21 percent of the Earth's atmosphere, that is capable of combining with all elements except some noble gases, that is active in physiological processes of almost all known organisms, and that is involved especially in the combustion
• Atomic number of Oxygen is 8 and atomic mass 16

Electronic configuration

The arrangement of electrons in energy levels around an atomic nucleus. According to the shell atomic model, electrons occupy several levels from the first shell nearest the nucleus being K.

Electronic configuration of Oxygen:- 2,6

According to the octet rule, the main-group elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.

• Cations are positive ions—they are positively charged because they have lost one or more electrons and therefore have more protons than electrons.
• Anions are negative ions—they are negatively charged because they have gained one or more electrons and therefore have more electrons than protons.

Therefore,

oxygen gains 2 electrons to reach the stable electronic configuration of Neon and becomes oxide anion

$\underset{2,6}{\mathrm{O}}+2{\mathrm{e}}^{-}\to {\underset{2,8}{\mathrm{O}}}^{2-}$

The symbol for oxide ion is ${\mathrm{O}}^{2-}$