Among the elements B, AI, C and Si, (a) which element has the highest first ionisation enthalpy? (b) which element has the most metallic character ? Justify your answer in each case.

Among the elements B, AI, C and Si, (a) which element has the highest

1.	Among the elements B, AI, C and Si, (a) which element has the highest first ionisation enthalpy? (b) which element has the most metallic character ? Justify your answer in each case.
Answer» Solution :The placing of elements are as On moving from left to right in a period the IONISATION enthalpy increase with DECREASE in atomic size and also it decreases when we go from top to bottom with increase in atomic size. Hence, carbon has the highest ionisation enthalpy. (b) Metallic CHARACTER decreases from left to right but increases from top to bottom the GROUP. Therefore, ALUMINIUM has the most metallic character.