What is the forumla for chlorine? anion

Letter a, because when there are unlike charges they will always attract to each other.

Answer (d) the universe had cooled enough for atoms to combine, protons and neutrons were too far apart to form nuclei;

Hellosubatomic particles  are  particles  that are smaller than the atom. protons, neutrons, and electrons are the three mainsubatomic particles  found in an atom. protons have a positive (+)  charge. an easy way to remember this is to remember that both neutron and no  electrical charge  start with the letter "n."have a nice day