three carboxylic acid residues

two carboxylic acid residues and one phosphate group

one carboxylic acid residue and two phosphate groups

three phosphate groups.

amount of adenine (A) is equal to that of thymine (T) and the amount of guanine (G) is equal to that of cytosine (C)

amount of adenine (A) is equal to that of guanine (G) and the amount of thymine (T) is equal to that of cytosine (C)

amount of adenine (A) is equal to that of cytosine (C) and the amount of thymine (T) is equal to that of guanine (G)

amounts of all bases are equal.

Fe (II)

Co (III)

Zn (II)

Ca (II)