PROPERTIES OF BERYLLIUM || ANOMALOUS BEHAVIOUR OF BERYLLIUM || BERYLLIUM ||

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 ANOMALOUS BEHAVIOUR OF BERYLLIUM

Beryllium(Be) is the first member of the Group 2 metals, which shows anomalous behaviour as compared to Magnesium(Mg) and rest of the members. Further, it shows diagonal relationship with aluminium.

» Beryllium(Be) has exceptionally small atomic and ionic sizes and thus does not compare well with other members of the group. Because of the high ionisation enthalpy(energy required to remove an electron from isolated gaseous ion) and smaller size it forms compound which are largely covalent and get easily hydrolysed.

» Beryllium(Be) do not exhibit coordination number more than 4 as in its valence shell there are four orbitals. The remaining member of this group can have a coordination number of 6 by making use of d-orbitals.

» The oxide and hydroxide(OH) of beryllium(be), unlike the hydroxides of other elements in the group, are amphoteric in nature.

» The beryllium hydride is electron deficient and polymeric, with multi-center bonding like aluminium hydride.

» The most unusual oxygen containing complexes of Be have formula  Be 4O (O 2 CR)6 and are formed by refluxing Be(OH)2 with carboxylic acids. These white crystalline compounds are soluble(can dissolve) in non-polar organic(carbon) solvents, such as alkanes, but are insoluble in water and lower alcohols. 

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