Provide examples to support the claim that phase changes are reversible

September 6, 2016 Diatomic Molecules  H 2  N 2  O 2  F 2  Cl 2  Br 2  I 2 Octet Rule  States that elements gain or lose electrons to attain an electron configuration of the nearest noble gases Atom  Proton  Neutrons gained or lost – isotopes  Electrons gained or lost – ions o When atoms gain or lose electrons, they become ions Na (Sodium) Na +  11 protons 11 protons #p > #e -  11 electrons 10 electrons  12 neutrons 12 neutrons Sodium atom Sodium ion Cl (Chlorine) Chlorine ion NaCl – Sodium Chloride +  17 protons 17 p  17 electrons