Which is greater, the number of compounds or the number of elements? the number of elements or the number of isotopes?

The fact that the total amount of energy in a system remains constant is a(n)

What is the effect of returning nuclear reactor cooling water back into bodies of water?

#7 how does the structure of amino acids allow them to form a polypeptide? each amino acid has an amino group and a carboxyl group. each amino acid has a hydrogen atom and a carboxyl group. each amino acid has a carboxyl group and an r group. each amino acid has an r group and a hydrogen atom.