Families of Elements

Groups

• Columns

• Elements in the same group have the same number of valence electrons

Periods• Horizontal Rows• As you move from

left to right the atomic number increases

• So the # of protons and electrons also increases

Alkali Metals

Alkali Metals• Are very reactive

• They only have one valence electron

Alkali Metals

• Lithium

• Sodium

• Potassium

Alkali Metals in Nature

• Because they are so reactive they are not found as elements in nature

• Instead they combine with other elements to form compounds

Alkaline Earth Metals

Alkaline Earth Metals

• Have two valence electrons

• Less reactive than the alkali metals

• Make bonds with other elements very easily

Calcium• Make up the

hard shells of many sea animals

• Found in bones and teeth

• Also found in green leafy vegetables

Magnesium• Used to build some airplanes

• Used in flares

• Activates many enzymes in the human body

Transition Metals

Transition Metals

• Not very reactive

• Conduct heat and electricity

Transition Metals• Copper is used for electrical wiring and

plumbing

• Light bulb filaments are made of tungsten

• Mercury is used in thermometers

All Metals

• Conduct heat and electricity

• Malleable

• High melting and boiling points

Bottom two rows of transition metals

• Keeps the table narrow so that similar elements still line up

• Elements with a atomic number higher than 92 are man-made

95 Americium

• Used in smoke detectors

Nonmetals• Found on the right

side of the periodic table

Carbon

• Found as graphite or diamonds in its pure state

Carbon Compounds

• Found in living and non-living things

• Glucose

• Chlorophyll

• Gasoline

• Rubber Tires

Glucose

C6H12O6

Gasoline

•C8H18

Sulfur Compunds

• Smells like rotten eggs

• But sulfur by itself does not smell

Chlorine• Used to kill bacteria in

swimming pools and drinking water

Noble Gases• Found on the

right side of the periodic table.

• Not very reactive at all because their valence electron shells are full.