Alkaline Earth Metals - by KB


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What are the Alkaline Earth Metals?

The Alkaline Earth Metals are the elements in group two of the Periodic table. These elements are Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium.

Properties of the Alkaline Earth Metals

external image 350px-Erdalkali.jpg

Alkaline Earth Metals are silvery white in color. They possess many of the properties of metals. They have low electron affinities and low electronegativities. They have two electrons in the outer shell and smaller atomic radii then the Alkali Metals. They are high in the reactivity series but not as high as the Alkali Metals. The Alkaline Earth Metals are harder and denser than Sodium and Potassium. They also have a higher melting point. All Alkaline Earth Metals except beryllium form oxides in air at room temperature. This dulls the surface of the metal. Barium is so reactive in air that it must be stored under oil.

Flame Test

When heated in a flame, four of these elements give off a characteristic color. This property is shown in the table below.

Element
Color
Example

Element
Color
Example
Magnesium
brilliant white
Mg-flame.jpg

Strontium
crimson
srflame.jpg
Calcium
brick-red
caflame.jpg

Barium
apple green
baflame.jpg

Sources
http://www.chemsoc.org/viselements/pages/data/intro_groupii_data.html
http://www.chemtopics.com/elements/alkaline/alkaline.htm
http://upload.wikimedia.org/wikipedia/commons/thumb/7/74/Erdalkali.jpg/350px-Erdalkali.jpg
http://www.ilpi.com/msds/ref/gifs/alkalineearths.gif
http://web1.caryacademy.org/chemistry/rushin/StudentProjects/ElementWebSites/magnesium/images/Mg-KClO3-flame.jpg
http://chemistry.about.com/library/weekly/aa010103e.htm