Why is F_2, Cl_2 gaseous room temperature while I_2 is a solid? Please give an answer relating to bond strength.

1 Answer
Sep 29, 2017

Well, the I-I bonds are MUCH weaker than those of F-F, and Cl-Cl.

Explanation:

However the physical state of the element is the result of "intermolecular bonding", the bonds between molecules, rather than "intramolecular bonding", the bonds within a molecule. Please note the distinction.

Because, iodine is a larger, more polarizable molecule, with a large electron cloud, the molecule has a greater degree of "intermolecular bonding", arising from dispersion forces, and is thus a room temperature solid.