Amino acids can be distinguished from one another by: a) the chemical properties of their amino and carboxyl groups. b) the number of R groups found on the amino acid molecules. c) the chemical properties of their R groups. d) the type of bond between the R group and the rest of the amino acid molecule.

The correct answer is c) the chemical properties of their R groups.

Explanation:

Amino acids are composed by a central carbon atom which is bonded to an amino group (-NH₂), a carboxyl group (-COOH) an hydrogen atom (-H), and a R group. The R group is a portion of molecule which varies from one amino acid and other. The R group confers to the aminoacid the characteristic chemical properties and defines it identity. For example, the strucutre of the aminoacid alanine (Ala) is the general squeleton is composed by the central C-atom, NH₂, -H and -COOH and its R group is a methyl group (-CH₃).

Amino acids are distinguished primarily by the chemical properties of their R groups. (C.)

Explanation:

Amino acids have three key features:

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.