Question

Explain in what respects lithium is different from other metals of the same group.

Answer 1

lithium:

• Very hard. 
• High melting and boiling point. 
• Least reactive. 
• Reacts with nitrogen to get Li₃N.
• Reacts with bromine slowly. 
• Burnt in air gives monoxide only. 
• Compounds are partially soluble in water. 
• Lithium nitrate decomposes to fòrm an oxide. 
• Extremely small in size. 
• Li⁺ has greater polarizing power.

Other elements of the family: 

• Very Soft. 
• Low melting and boiling point. 
• More reactive. 
• No reaction. 
• Reacts violently. 
• Burnt in air gives peroxides also, apart from monoxides. K, Rb and Cs gave super oxides. 
• Highly soluble in water. 
• Other metals on heating gives nitrite. 
• Comparatively large in size. 
• Other M⁺ ions have comparatively larger polarizing power.