Question

Sodium reacts with chlorine to form the compound sodium `2Na + Cl_2 -> 2NaCI`. How would you describe, in terms of electron arrangement, the type of bonding in a molecule of chlorine?

Answer 1

There is a single covalent bond in a chlorine molecule.

Explanation:

The chlorine molecule is represented as `Cl-Cl`, i.e. `Cl_2`. Between the chlorine atoms, 2 electrons overlap to form a region of high electron density to which the positively charged chlorine nuclei are attracted, such that internuclear repulsion is negated and a net attractive force results. Because the bonding electrons are shared between the nuclei, we conceive that each atom has 8 valence electrons.

Of course, on reaction with sodium, the sodium reduces the chlorine molecule to give `2xxCl^-`. The resultant bond between `Na^+` and `Cl^-` is ionic and a non-molecular substance results.