Answer: B. a molecule
Explanation: Covalent bond is formed by the sharing of electrons between atoms.
[tex]H_2[/tex] is a molecule formed by the sharing of electrons between two hydrogen atoms.
An ion is formed by losing or gaining electrons.
[tex]Na^+:10:[Ne][/tex]
A neutral atom is one which contains equal number of protons and neutrons.
[tex]Na:11:[Ne]3s^1[/tex]
A noble gas is one which contains completely filled orbitals.
[tex]Ne:10:1s^22s^22p^6[/tex]
