Groups of the Periodic Table of Elements Metals vary in Shininess - Malleablility- Ductility- Conductivity- Reactivity-

Alkali Metals – Group 1 The most reactive metals. React with other elements by losing 1 electron So reactive they are never found alone in nature. Examples—Na sodium and K potassium

Alkaline Earth Metals-Group 2 React by losing 2 electrons Good conductors of electricity Not as reactive as Group 1 but more reactive than most metals Are also never found uncombined in nature Examples Mg magnesium and Ca calcium

Transition Metals-Groups 3-12 Includes familiar metals such as Fe iron Cu copper Au gold Ag silverNi nickel Most are hard and shiny Good conductors of electricity Not very reactive other than they rust- oxidation Many form colorful compounds ( used in paints )

Metals in Mixed Groups Groups Only some are metals –MIXED groups Less reactive Al aluminumSn tinPb lead

Carbon Family-Group 14 Carbon is the only element in Group 14 that is a nonmetal These elements gain, lose, or share 4 electrons Carbon is found in all living things = organic Most fuels contain carbon

Nitrogen Family-Group 15 N nitrogen and P phosphorus are nonmetals Gain or share 3 electrons

Oxygen Family-Group 16 Gain or share 2 electrons Contains 3 nonmetals – O oxygen – S sulfur – Se selenium Oxygen is highly reactive and can combine with almost every element.

Oxygen Oxygen exists as O 2 (a diatomic molecule) in the air we breathe Oxygen also forms O3 called ozone ( a triatomic molecule ) which collects in the upper atmosphere where it screens out harmful radiation from the sun. Ozone is a dangerous pollutant at ground level because it is highly reactive. Oxygen is the most abundant element in Earth’s crust and the second-most abundant element in the atmosphere. (The first is nitrogen.)

Halogen Family-Group 17 Halogens are nonmetals except for At astatine Fl flourine Cl chlorine Br bromine and I iodine – are the most reactive nonmetals – Have similar properties-gain or share one electron – Salt forming – Very reactive – Uncombined elements are dangerous to humans

More on Halogens Fl is so reactive it reacts with almost every other known substance. Water will burn in Fl Cl gas is extremely dangerous- but ok in small amounts to kill bacteria in water. Br liquid will burn skin

Noble Gases-Group 18 Do not ordinarily form compounds because atoms of noble gases do not usually gain, lose or share electrons. Stable-unreactive 8 valence electrons (except helium which has 2)

Hydrogen Can not be grouped into a family because it is so different.

Metalloids Along the border between metals and nonmetals Have characteristics of both metals and nonmetals Varying ability to conduct electricity depending on temperature light impurities – makes them useful in semiconductors.

Lanthanides Top row at bottom of periodic table Soft, malleable, shiny metals High conductivity Mixed with more common metals to make alloys. Alloy-mixture of a metal with at least one other element.

Actinides Row of elements at bottom of Periodic Table below the Lanthanides. U uranium is used to produce energy in nuclear power plants Nuclei are very unstable-break apart quickly Synthetic Elements atomic # above 92 are man made by particle accelerators which force atoms to crash together. Exception—Neptunium and ___have been found in nature