Chapter 25, Problem 1SAQ

Interpretation Introduction

Interpretation: The correct electron configuration of the Cu⁺ ion is to be identified from the following given options:

a) $\left[Ar\right]4s^{2}3d^9$

b) $\left[Ar\right]4s^{2}3d^8$

c) $\left[Ar\right]4s^{1}3d^9$

d) $\left[Ar\right]4s^{0}3d^{10}$

Answer to Problem 1SAQ

Solution: (d)

Explanation of Solution

When we write the electron configuration of $C{u}^{+}$ ion using the periodic table,

we see that argon is the noble gas that precedes copper, so we write it in square brackets: $\left[Ar\right]$.

Now we know that Cu is in the fourth period, so the orbitals used are $\left[Ar\right]4s3d$

and Cu has 11 more electrons than Ar. Fill the orbitals accordingly: $\left[Ar\right]4s^{2}3d^9$.

We know that the half-filled and completely filled orbitals are more stable, so the correct configuration for Cu would be $\left[Ar\right]4s^{1}3d^{10}$.

$C{u}^{+}$ has lost one electron relative to the Cu atom (removed from the s orbital). The electron configuration of the $C{u}^{+}$ ion is $\left[Ar\right]4s^{0}3d^{10}$.

Conclusion

Hence, the correct option is (d).