question_answer

The ionization energies of elements U, V, W and X are 2480, 550, 950 and 1690 kJ mol-1 respectively. Which of the statements about these elements are correct?

(i) V is a reactive metal.

(ii) X is a reactive non-metal.

(iii) U is a noble gas.

 

A) (i) and (ii) only  

B) (ii) and (iii) only

C) (i) and (iii) only 

D) All of these

Correct Answer: D

Solution :

As we move across a period from left to right, ionization energy increases due to decrease in atomic size. V is a reactive alkali metal which has low value of first ionization energy and loses one electron easily to form monovalent cation. X is a reactive non-metal which has high value of first ionization energy thus, it prefers to gain electron rather than losing. U having very high value of ionization energy is a noble gas which has stable, completely filled electronic configuration and is chemically inert.