Periodic Table What we already know: Periodic Law: when Atoms arranged by increasing atomic number, patterns appear Rows = Periods Columns = Families or Groups Elements within a group or family have similar properties

Why do groups have similar properties? Valence electrons- electrons in outer energy level Elements in a group have similar properties because they have valence electrons in similar configurations

Metals, Nonmetals, Semimentals Separated by staircase black line on right side of periodic table Metals on left side Nonmetals on right side Semimetals border the black line

Properties of Metals Have luster (shiny) Conductors of electricity Malleable- can be hammered into thin sheets (example: aluminum or tin foil) Usually solids at room temperature

Properties of Nonmetals Opposite of metals Not shiny Do not conduct electricity Not malleable. They are brittle Usually a gas at room temp Fantastic seven- these are diatomic, written N 2 instead of N

Semimetals Also known as metalloids Properties of both metals and nonmetals

Alkali Metals 1 st column in blue End in s 1

Alkaline Earth Metals 2 nd column – green End in s 2, full s sublevel

Alkali Metals & Alkaline Earth metals Soft metals- you can cut them with a knife EXTREMELY reactive (especially alkali metals) Why so reactive? What sort of charge do they form?

Transition Metals Middle – purple Electrons being added to the d sublevel

Inner transition Metals F- block (beige color) Electrons being added to the f sublevel

Transition metals and Inner transition metals Harder metals Not as reactive as alkali & alkaline earth Can change their number of valence electrons (this is why they are called transition metals– no set charge) Always give up valence electrons (form a positive charge- +1, +2, +3, or +4)

Non-Metals Right of the stair-step line

Halogens Group 7A(light orange) Always end in s 2 p 5

Halogens Most are gases Most are diatomic Used in Halogen lights Very reactive- Why? What kind of charge do they form?

Noble Gases Group 8A (yellow) s 2 p 8 (full s and p sublevels)

Noble Gases Gases at room temp. Extremely UNREACTIVE = inert Why so unreactive?