What happens during chemical reactions?

If the atomic mass of an atom is 34 and the atom contains 13 protons, how many neutrons does the atom contain?

Answer explain why it is not possible to deduce a complete order of reactivity.

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent