Assertion (A): Copper (Z = 29) with electronic configuration [Ar] 4s1 3d10 is more stable than [Ar] 4s1 3d10 . Reason(R): Copper with [Ar] 4s2 3d9 is more stable due to symmetrical distribution and exchange energies of d electrons. (a) A and R are correct and R is the correct explanation of A. (b) A and R are correct but R is not the correct explanation of A. (c) A is correct but R is wrong. (d) A is wrong but R is correct.

Assertion (A): Copper (Z = 29) with electronic configuration [Ar] 4s1

1.	Assertion (A): Copper (Z = 29) with electronic configuration [Ar] 4s1 3d10 is more stable than [Ar] 4s1 3d10 . Reason(R): Copper with [Ar] 4s2 3d9 is more stable due to symmetrical distribution and exchange energies of d electrons. (a) A and R are correct and R is the correct explanation of A. (b) A and R are correct but R is not the correct explanation of A. (c) A is correct but R is wrong. (d) A is wrong but R is correct.
Answer» (a) A and R are correct and R is the correct explanation of A