Question

What do oxygen atoms and oxide ion have in common?
(A) same size
(B) same number of electrons
(C) same electronic configuration
(D) same number of protons

Answer 1

Hint: As we know that, ion of any compound or molecule or atom is not in the native state in which any compound or molecule, atom exists. So, ions may be formed by dissolving in solvent or applying external energy. The ion may be formed by losing or gaining electrons.

Step by step answer:
As we know that, an oxygen atom is present at the right side in the periodic table which exists in oxygen gas. It has zero charge in this state also known as oxidation state.
Oxide ion exists when oxygen is dissociated from any compound. It is represented as \[{{\rm{O}}^{2 - }}\]which means that 2 electrons are added to complete the octet.
Let’s see the options.

Option (A) same size- oxygen atom and oxide ion cannot have same size because the oxygen atom has only eight electrons and 8 protons but the oxide ion is formed by adding two extra electrons in the oxygen atom, due to adding electrons in the outermost shell repulsion occurs between the electrons of oxygen atom hence size of oxide ion increases.
Both oxygen atom and oxide ion cannot have the same number of electrons as we have seen in the above explanation.so. the option (B) is also not correct.
The electronic configuration of oxygen atom and oxide ion is as follows:

\[{\rm{O}} = {\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{4}}}\]
\[{{\rm{O}}^{2 - }}{\rm{ = 1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^6}\]

Therefore, the option (C) is also not correct.
The protons of oxygen and oxide ion are the same, both contain eight protons. So, option (D) is the correct option.

Note: The nucleus consists of protons and neutrons and we cannot change the number of protons because deep into the atom only the numbers of neutrons can be changed because it depends upon the electrons.