5.3 Chemical Families

Elements within the same family of the periodic table have similar properties because they have the same number of valence electrons.

The Most Active MetalsAlkali Metals•Family 1•Hydrogen isn’t considered an alkali metal•1 valence electron•Soft, silver-white, shiny metals•Good conductors of heat and electricity•Extremely reactive (react violently with water)•Never found uncombined in nature

Alkaline Earth Metals:•Family 2 of Periodic Table•Never found in nature uncombined•2 valence electrons•Lose the 2 electrons•Not quite as reactive•High melting & boiling points•Silver in color

Transition MetalsTransition metals•Families 3 through 12•Properties similar to one another and other metals•Copper, tin, zinc, iron, nickel, gold, and silver•Good conductors of heat & electricity•1 or 2 valence electrons•Lose 1 or both electrons when combining with other atoms

From Metals to NonmetalsBoron Family•3 valence electons•Boron is a metalloid•Other elements, including aluminum, are metals•Boron is hard and brittle•Aluminum is 3rd most abundant metal in Earth’s crust

Carbon Family•Family 14•Atoms have 4 valence electrons•Carbon is nonmetal•Silicon and germanium are metalloids•Tin and lead are metals•Silicon is 2nd most abundant element in Earth’s crust

Nitrogen Family•Family 15•Atoms have 5 valence electrons•Share electrons when they bond with other atoms.•Nitrogen is most abundant (78%) element in Earth’s atmosphere

Antimony, white & red phosphorus, bismuth, and arsenic all have five electrons in the outermost energy level of their atoms. Nonetheless, they are strikingly different from each other in both physical properties and chemical behavior. Nitrogen is a nonmetallic gas; phosphorus is a solid nonmetal; arsenic and antimony are metalloids; and bismuth is a typical metal.

Oxygen Family•Family 16•Atoms have 6 valence electrons•Elements share electrons when forming compounds•Oxygen is most abundant element in Earth’s crust•Oxygen forms ozone (O3)

The HalogensHalogen Family•Family 17•Atoms have 7 valence electrons•Most active nonmetals•1 electron will fill outer energy level•Very reactive•Never found free in nature•React with alkali metals very easily•Fluorine is most active halogen

The Noble GasesNoble Gases•Family 18•All elements are unreactive•Also called inert gases•Except for helium, all elements have 8 valence electrons•All noble gases are found in Earth’s atmosphere•Radon is used to treat certain cancers.

Rare-Earth ElementsLanthanide Series•Soft, malleable metals•High luster & conductivity

Actinide Series•All actinides are radioactive