Re: What is the relationship between atomic mass, and specific heat?

Specific heat is the ratio between the change of internal energy and the change in temperature. Sometimes it is called specific heat capacity, or just heat capacity.

Recall that temperature is proportional to the average kinetic energy of the molecules. Different substances have different specific heats because energy added to the substance is divided differently. For example, some of the energy could go into increasing vibrational or rotational motion or breaking noncovalent bonds. Only a portion of the energy goes into increasing the kinetic energy, i.e. increasing the temperature.

All else being equal, one would expect that a molecule with more bonds would have a higher specific heat than a molecule with fewer bonds. This is because energy added to the material has more places to go (bond vibration) in the former substance, and kinetic energy doesn't increase as much. So, as a general trend, molecules with larger atomic mass have higher specific heats. However, because specific heat is also dependent on the chemistry of the molecules (eg polarity, shape, bonds etc.), that statement often does not work. There is no specific mathematical relationship between specific heat and atomic mass. Usually, tables of specific heat values are prepared based on experimental measurements.

Your MAD Scientist,
Raymond Cheong

"Thermodynamics is a funny subject. The first time you go through the subject, you don't understand it at all. The second time you go through it, you think you understand it, except for one or two small points. The third time you go through it, you know you don't understand it, but by that time you are so used to the subject that it doesn't bother you any more."
-- A. Sommerfeld

Some more info on specific heat: ht tp://physicsstudio.indstate.edu/StudioLabs/SpecificHeat.htm