Answer: Nuetrons, protons, electrons, elements and compounds
Explanation: Atoms are the smallest components of matter and it is comprised of these three subatomic particles; nuetrons, protons and electrons. Next in the order are the elements (found in periodic table). Elements are made of atoms and compounds are large molecules made of elements. Elements are pure substances that cannot be broken down into smaller substance by chemical reactions whereas compounds can be broken down further.
I don't know the real answer because you didn't attach the choices, but Adenine (A) is always paired with Thymine(T) and Guanine (G) is always paired with Cytosine (C).
