What element of an amino acid makes it different from other types of amino acids?

The R group.

Explanation:

The basic structure of all amino acids are a central carbon atom attached to a hydrogen atom with a single bond. This carbon atom is also connected to an amino/amine group, NH2, and a Carboxyl Group, COOH. What differentiates amino acids from each other is the R group that is attached to the carbon atom as well, as it is unique to each amino acid. Thus, the R group is the element of an amino acid that makes it different from other types of amino acids. Hope this helped!

a. as the temperature increases, the kinetic energy of the gas molecules increases & the molecules move faster & further away from each other.

b. if you decrease the temperature of a fixed amount of gas at constant pressure, the combined gas law reduces to charles's law. in this case, volume will also decrease.