CBSE Class 11-science Answered

Some important points of difference between beryllium and other members (especially magnesium) are given below:

(i) Be is harder than other members of its group.

(ii) Be is lighter than Mg and other elements of the group.

(iii) Its melting and boiling points are higher than those of Mg and other members.

(iv) Be does not react with water while Mg reacts with boiling water.

(v) BeO is amphoteric while MgO is weakly basic.

(vi) Be forms covalent compounds whereas other members form ionic compounds.

(vii) Beryllium carbide reacts with water to give methane whereas carbides of other alkaline earth metals give acetylene gas.

(viii) Beryllium does not exhibit coordination number more than four as it has four orbitals in the valence shell. The other members of this group has coordination number 6.