alkali metals![click to hear](/images/speaker.jpg)
Generally soft and silvery and very good conductors of heat and electricity; they are very reactant with nonmetals and break down in cold water.
francium ![click to hear](/images/speaker.jpg)
The heaviest of the alkali metals is very rare and radioactive and has a very short life span (about 22 minutes).
cesium ![click to hear](/images/speaker.jpg)
Rare metal that is used especially in photoelectric cells, atomic clocks, infrared lamps and treating certain cancers.
rubidium ![click to hear](/images/speaker.jpg)
Metal similar to potassium but much rarer that is used in the manufacture of photoelectric cells and special kinds of glass and lasers.
potassium ![click to hear](/images/speaker.jpg)
Very reactant light metal that is used especially in fertilizer and matches; its salts are used in medicine.
sodium ![click to hear](/images/speaker.jpg)
Metal that is used especially in streetlights, kitchen salt (sodium chloride) and the manufacture of glass and cosmetic products.
lithium ![click to hear](/images/speaker.jpg)
The lightest of all the metals is used especially in alloys for the aerospace industry, in household batteries and in medicine.