Chapter 7, Problem 2STP

Interpretation Introduction

Interpretation:

The statement is to be identified which is not true regarding ${\text{Sc}}^{\text{3+}}$ ion.

Concept introduction:

Scandium is a group 3, d −block elements. The characteristic of scandium element issimilar between aluminium and yttrium. There is a diagonal relation between magnesium and scandium.

Answer to Problem 2STP

Option C is correct answer as it is the false statement regarding ${\text{Sc}}^{\text{3+}}$ ion.

Explanation of Solution

Reason for correct option:

According to option C statement ${\text{Sc}}^{\text{3+}}$ is considered to be a different element than a neutral Sc atom.

${\text{Sc}}^{\text{3+}}$ has the same electron configuration as argon. It is still a Scandium nucleus with 21 protons. The number of protons identifies the element. Therefore, the statement is false.

Conclusion

Reason for incorrect option:

A. It has the same electron configuration as argon. Ar has 18 electrons while neutral Sc has 21 electrons. In ${\text{Sc}}^{\text{3+}}$, it loses 3 electrons and then it has 18 electrons. Hence, ${\text{Sc}}^{\text{3+}}$ and Ar have the same electron configuration. The statement is correct regarding ${\text{Sc}}^{\text{3+}}$ ion.

B. The statement is true that means ${\text{Sc}}^{\text{3+}}$ is scandium ion with three positive charge.

D. The electron configuration of Sc is as follows:

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{4s}}^{\text{2}}{\text{3d}}^{\text{1}}$. The ${\text{Sc}}^{\text{3+}}$ ion is formed by the removal of two 4s electrons and one 3d electron. 4s and 3d very similar and the electrons that reside them are considered valance electrons. Therefore, the statement is correct.