Answer:
A hydrogen atom is an atom of the chemical element hydrogen.Carbon is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds.
In chemistry, an element is a pure substance consisting only of atoms that all have the same numbers of protons in their atomic nuclei.
Explanation:
They are found in proteins
Answer:
I'm pretty sure it's a protein building block
B, If I remember correctly. Oldest ones are always at the bottom, newest are at the top.