The Periodic Table

The Modern Periodic Table Arranged in order of increasing atomic number

Properties of Elements Metals Metalloids Nonmetals

Metals – MOST of the Periodic Table 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

Nonmetals – upper right corner Variation in properties Not metals Mostly gases at room temperature Generally, poor conductors Solids tend to be brittle

Metalloids – the “stairstep” Properties similar to metals and nonmetals Behavior (metal or nonmetal) depends on conditions

Periodic Law When arranged in order of increasing atomic #, elements show similar properties within groups (this has to do with their electron configurations). Group = column Period = row

Group 1A: Alkali Metals Most reactive metals: 1 VALENCE ELECTRON

Group 2A: Alkaline Earth Metals Less reactive than Group 1A metals: 2 valence electrons Alkaline Earth Metals

Group 7A: Halogens Most reactive nonmetals: 7 valence electrons

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

B-Groups: Transition Metals