I think it’s C atomic radius and numbers of unshielded protons
Answer:
because no chemical change is happening
Explanation:
The amino acids are the molecules where we can found the carboxyl group (-
), amino group (-
), hydrogen atom (H) and a residual R-group. On the structure of the residual R-group the name of the amino acid depends. Like if R is hydrogen (H) the amino acid is alanine; If R- group is a phenyl group i.e. 
, the compound is called phenyl alanine. The structure of the general amino acid skeleton can be shown as-
