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प्रश्न
Explain the important common features of Group 2 elements.
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उत्तर
- Group 2 elements except beryllium are commonly known as alkaline earth metals because their oxides and hydroxides are alkaline in nature and these metal oxides are found in the Earth’s crust.
- Many alkaline earth metals are used in creating colours and used in fireworks.
- Their general electronic configuration is ns2.
- Atomic and ionic radii of alkaline earth metals are smaller than alkali metals, on moving down the group, the radii increases.
- These elements exhibit a +2 oxidation state in their compounds.
- Alkaline earth metals have higher ionization enthalpy values than alkali metals and they are less electropositive than alkali metals.
- Hydration enthalpies of alkaline earth metals decrease as we go down the group.
- Electronegativity values of alkaline earth metals decrease down the group.
- Alkaline earth metal salts moistened with concentrated hydrochloric acid gave a characteristic coloured flame when heated on a platinum wire in a flame.
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संबंधित प्रश्न
Discuss the general characteristics and gradation in properties of alkaline earth metals.
Assertion: Generally alkali and alkaline earth metals form superoxides.
Reason: There is a single bond between O and O in superoxides.
Assertion: BeSO4 is soluble in water while BaSO4 is not
Reason: Hydration energy decreases down the group from Be to Ba and lattice energy remains almost constant.
In context with beryllium, which one of the following statements is incorrect?
Beryllium halides are covalent whereas magnesium halides are ionic why?
The reducing power of a metal depends on various factors. Suggest the factor which makes Li, the strongest reducing agent in aqueous solution.
When sodium is dissolved in liquid ammonia, a solution of deep blue colour is obtained. The colour of the solution is due to ______.
Discuss the trend of the following:
Thermal stability of carbonates of Group 2 elements.
Among the following alkaline earth metal halides, one which is covalent and soluble in organic solvents is ______.
Given below are two statements:
Statement I: Colourless cupric metaborate is reduced to cuprous metaborate in a luminous flame.
Statement II: Cuprous metaborate is obtained by heating boric anhydride and copper sulphate in a non-luminous flame.
In the light of the above statements, choose the most appropriate answer from the options given below.
