  Liquid:  Hg and Br  Gas:  all the noble gases (group 18)  and O, F, N, H, Cl  Solid:  rest of the elements in the periodic table 3 states of matter

  All elements are classified as either:  Metals  Nonmetals  Semi-metals/metalloids

  Left and middle of periodic table except H  Properties:  Ductile: drawn into a wire  Malleable: hammered into thin sheets  Good conductors of heat/electricity  Luster: shine  Solid at room temperature (except for Hg) Metals

  Far right side of periodic table  Properties  Brittle: break when hammered  Lack luster  Poor conductors  Solid or gas at room temperature (except Br) Nonmetals

  Along the black line that divides metals and nonmetals  Have properties of both metals and nonmetals Metalloids (Semi-metals)

  Elements in the same group have the same chemical and physical properties  Example:  Noble gases- Group 18  All gases  All unreactive  Same number of electrons in last energy level Periodicity

  Electrons in the last energy level of an atom  Involved in chemical reactions and bonding  Number of valence electrons coincides with the unit’s place on the group number except for transition metals  Group 1: 1 valence electron  Group 2: 2 v.e.  Group 18: 8 v.e. except for He Valence electrons

  Shows the number of valence electrons in a neutral atom  Each dot represents 1 valence electron Lewis Dot Diagram

 Distance between nucleus and valence electrons – radius increases as you move down a group – Radius decreases as you move across a period Same energy level in a period but more protons across a period to attract valence electrons closer Atomic Radius

 Measure of the ability to attract and share electrons – (force between nucleus and valence electrons) Increases across a period Decreases down a group Noble gases have no electronegativity they do not share electrons Electronegativity