25-01-2013, 04:22 PM
THE s-BLOCK ELEMENTS
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Alkali metals. The group-1 elements, lithium, sodium, potassium, rubidium, caesium and francium.
Lithium is the lightest metal.
Lithium shows diagonal relationship with Mg.Alkali metals have lowest ionization enthalpies and largest atomic radii in their respective periods.
The hydration enthalpies of alkali metals ions are in the order. Li⁺ > Na⁺ > Rb⁺ > Cs⁺
Sodium is the most abundant alkali metals in the earth crust.
Alkali metals behave as strong reducing agents due to their low ionization enthalpies.
All alkali metals impart characteristic colour to the flame. Li-caramine red , Na-golden yellow, K-pale violet, Rb-reddish violet and Cs-sky-blue.
Caesium, due to its very low ionization enthalpy, is used in photo electric cells.
Alkali metals due to their large atomic size, have very weak metallic bond. That is why they can be cut with the help of a knife.
[attachment=48503]
Alkali metals. The group-1 elements, lithium, sodium, potassium, rubidium, caesium and francium.
Lithium is the lightest metal.
Lithium shows diagonal relationship with Mg.Alkali metals have lowest ionization enthalpies and largest atomic radii in their respective periods.
The hydration enthalpies of alkali metals ions are in the order. Li⁺ > Na⁺ > Rb⁺ > Cs⁺
Sodium is the most abundant alkali metals in the earth crust.
Alkali metals behave as strong reducing agents due to their low ionization enthalpies.
All alkali metals impart characteristic colour to the flame. Li-caramine red , Na-golden yellow, K-pale violet, Rb-reddish violet and Cs-sky-blue.
Caesium, due to its very low ionization enthalpy, is used in photo electric cells.
Alkali metals due to their large atomic size, have very weak metallic bond. That is why they can be cut with the help of a knife.