The moment the question mention Diamond, suspect Carbon as the answer. (1) element: C, carbon. Atomic number: 12 (double check on periodic table). (2) Not sure what does the question means, but I guess in the first shell, there will be 2 electrons and the 2nd shell will have 8 electrons (may need to explain it based on electron configuration involving s,p,d and f orbitals). (3) MOST undergoes sharing of electron so they form covalent bond with non metals.
