The Ten Chemmandments
Created by: Mark Rosengarten

I) Laws of Conservation: Matter, Energy and Charge Cannot Be Created or Destroyed by Physical or Chemical Change. Energy can be converted from one form to another.

II) Opposite Charges Attract, Like Charges Repel. The Greater the charges are, the greater the attractive or repelling forces.

III) Covalent Bonds are formed when two nonmetal atoms share their unpaired valence electrons. Each bond is a pair of shared electrons.

IV) Ionic Bonds are formed when a metal atom loses its valence electrons to a nonmetal atom. The metal forms a + ion, the nonmetal forms a – ion and the oppositely charged ions attract.

V) Octet Rule: When atoms form chemical bonds, they will end up with eight valence electrons, the same number as a noble gas.

VI) Acids dissolve in water to yield H+ as the only positive ion in solution; Bases dissolve in water to yield OH- as the only negative ion in solution.

VII) Metals have low electro-negativity, therefore they tend to lose electrons (oxidize) and form + charged cations. Nonmetals have high electronegativity, therefore they tend to gain electrons (reduce) and form – charged anions.

VIII) Atomic Number is the number of protons, as well as electrons, in a neutral atom and identifies an element. Atomic Mass is the number of particles in the nucleus (protons plus neutrons) and identifies an isotope.

IX) As attractive force strength increases between molecules, the melting and boiling point increase and the vapor pressure decreases. 

X) Group 1 (alkali metals), Group 2 (alkaline earth metals) and Group 17 (halogens) are so reactive they are only found in compounds. Groups 3-12 (transition metal) form colored compounds.