Arranged in order of increasing atomic number

Metals Metalloids Nonmetals

•Good conductors of heat and electric current•High luster or sheen (shiny)•Solids at room temperature (except for Hg)•Ductile•Malleable•MORE REACTIVE ON LEFT

•Variation in properties•Not metals•Mostly gases at room temperature•Generally, poor conductors•Solids tend to be brittle

•Properties similar to metals and nonmetals•Behavior (metal or nonmetal) depends on conditions

When arranged in order of increasing atomic #, elementsshow similar properties within groups (this has to do withtheir electron configurations).

Group = columnPeriod = row

•Most reactive metals: 1 VALENCE ELECTRON

AlkaliMetals

Less reactive than Group 1A metals: 2 valence electrons

AlkalineEarthMetals

•Most reactive nonmetals: 7 valence electrons

Halogens

•“Inert Gases:” 8 valence electrons (except for He – 2)•Rarely react because highest energy level is FULL.

NobleGases

•Transition metals

transitionmetals