Answer: B. a molecule
Step-by-step explanation: Covalent bond is formed by the sharing of electrons between atoms.
is a molecule formed by the sharing of electrons between two hydrogen atoms.
An ion is formed by losing or gaining electrons.
![Na^+:10:[Ne]](https://img.qammunity.org/2019/formulas/chemistry/middle-school/7qssinjf8a9mk6za6k1qh2xqsetu75zkbq.png)
A neutral atom is one which contains equal number of protons and neutrons.
![Na:11:[Ne]3s^1](https://img.qammunity.org/2019/formulas/chemistry/middle-school/9mmkbcsmd3paf9b6gy65l23j9f55a122a9.png)
A noble gas is one which contains completely filled orbitals.
