Tour of the Periodic Table

The Main Group Elements Consist of groups 1,2 and 13-18 (everything blue) Electrons are consistent: the elements in each group (column) have the same number of valence electrons

Group 1: Alkali Metals Alkali metals are so named because they are metals that react with water to make alkaline solutions Have 1 valence electron – that’s 1 electron away from being happy (full shells) so they bond with other elements to get rid of the electron So highly reactive, they are never found in pure form in nature – always combined with other elements For example: NaCl (table salt, salt water) Does not include hydrogen

Group 2: Alkaline-Earth Metals Second most reactive group of elements in the PT Named alkaline metals because when in solution, they form basic (or alkaline) solutions with a pH above 7. Have 2 valence electrons – give up 2 electrons by bonding to become HAPPY and get a full outer shell Best known: calcium – important mineral in human body

Group 17: Halogens Halogen – Greek “salt maker” 7 valence electrons 1 electron shy of having a full shell – so VERY REACTIVE Most reactive element in group – fluorine React with alkali metals to create salts – i.e. NaCl

Group 18: The Noble Gases Have a full set of electrons in their outermost energy level UNREACTIVE – stable from full outer shell Helium used to fill blimps because it is non-flammable, and is lighter than air

Hydrogen: Class of Itself Most common element in universe With only 1 electron, hydrogen can react with MANY other elements Component of organic molecules (us), and is used commercially in production of fertilizer

Metals, Nonmetals, Metalloids

Metals Majority of elements are metals Excellent conductors of electricity (think of wires – what are they made of?) Excellent conductors of heat (what does a seat belt feel like in a hot car?) Ductile – can be squeezed into wire Malleable – can be hammered or rolled into sheets Solid (except mercury)

Transition Metals Group 3-12 DO NOT have identical outer electron configurations Not very reactive, often found in nature as pure elements Good conductors of heat and electricity Ductile and malleable

Nonmetals Elements to the right of the line are nonmetals Have properties opposite those of metals Brittle, non conductors of heat and electricity Some are liquid

Metalloids Along staircase border Cross between metals and nonmetals Act as semi-conductors – useful in computer chip industry i.e. silicon (Silicon Valley)

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