Question

Heat capacities are chemical-system specific. Provide a molecular-level description of Argon to account for this specificity.

Answer 1

When any material is heated the kinetic, vibrational, rotational, and electronic energies of the particles increase and as a consequence the temperature of the body increases. Heat capacity is a measure of the heat required to increase the temperature of any material by unit temperature. So, molecules which have vibrational and rotational changes associated with them will have higher heat capacities.

Argon being a mono atomic molecule does not have these modes of energy absorbance. Therefore the specific heat of Argon is lower as compared to other lements of that period.