4.2.1 - The Alkali Metals
4.2 - The Groups
The alkali metals: Li, Na, K, Rb, Cs,
the alkali metals.
- grey, soft metals that can be cut with a knife.
- low densities
- good conductors of heat and electricity
- alkali metals react with water, oxygen, and other chemicals
- alkali metals are never found as free elements
in nature (i.e. - sodium metal does not exist as Na metal in
nature, sodium exists in compounds such as NaCl, Na2CO3,
- alkali metal compounds are water soluble and are present in seawater
and salt deposits.
- all alkali metals have one valence electron (section
3.3) which form ions with a positive (1+) charge
- since alkali metals react quickly with oxygen, they are stored under
mineral oil or kerosene.
- sodium and potassium are the most common; they are the 6th and 7th
most abundant elements in the Earth's crust.
- sodium chloride, NaCl; found in seawater
- potassium chloride, KCl; used in fertilizers
Follow this interesting link to see more
pictures of the elements:
Periodic Table Periods and Groups ..p106
Characteristics of the Groups ..p109