Thursday, January 31, 2008

AIEEE Chemistry Unit 14A S-Block Elements

ALKALI AND ALKALINE EARTH METALS
Group - 1 and 2 Elements:
General introduction, electronic configuration and general trends in physical and chemical properties of elements,


The alkali metals are the elements located in Group IA of the periodic table.

The alkali metals have many physical properties common to metals, but their densities are lower than those of other metals.

Alkali metals have one electron in their outer shell.

This gives them the largest atomic radii of the elements in their respective periods.

Their low ionization energies result in their metallic properties and high reactivities.

An alkali metal can easily lose its valence electron to form the univalent cation.

Alkali metals have low electronegativities.

They react readily with nonmetals, particularly halogens.



ALKALINE EARTH METALS

The six alkaline earth metals—beryllium, magnesium, calcium, strontium, barium, and radium—comprise Group 2 on the periodic table of elements.

They are in Group 2 beside the alkali metals in Group 1, and as their names suggest, the two families share a number of characteristics, most notably their high reactivity.

Magnesium and calcium have a number of uses, ranging from building and other structural applications to dietary supplements.

In fact, both are significant components in the metabolism of living things—including the human body.

Barium and beryllium have numerous specialized applications in areas from jewelry to medicine, while strontium is primarily used in fireworks.

Radium, has radioactive qualities.

No comments: