Chapter 7, Problem 80A

Interpretation Introduction

Interpretation:

The relation between name Scandium(III) oxide in terms of electrons gained or lost needs to be explained and the correct formula needs to be identified.

Concept introduction:

Ionic bonds are formed when there is complete transfer of electrons from one atom to another. These atoms either lose or gain electrons to become negatively or positively charged ions. The forces of attraction between these ions cause the ionic bond formation. Ionic compounds are formed only when there is a balance between their charges.

Answer to Problem 80A

The element Scandium will lose 3 electrons to form ${\text{Sc}}^{\text{3+}}$ and oxygen gains 2 electrons to form ${\text{O}}^{2-}$ and these will combine to give compound ${\text{Sc}}_2{\text{O}}_3$.

Explanation of Solution

The element Scandium belongs to Group 3 and is the first element in this group.

Its atomic number is 21 and its electronic configuration is ${\text{1s}}^2{\text{2s}}^2{\text{2p}}^6{\text{3s}}^2{\text{3p}}^{6}3{\text{d}}^1{\text{4s}}^2$.

It has 3 valence electrons in its outermost shells and can donate these 3 electrons and become ${\text{Sc}}^{\text{3+}}$.

The element oxygen belongs to group 16 and its atomic number is 8. The electronic configuration is ${\text{1s}}^2{\text{2s}}^2{\text{2p}}^4$. It has 6 valence electrons and needs 2 more electrons to get its octet configuration. Hence, it will form ${\text{O}}^{2-}$.

Therefore, combining ${\text{Sc}}^{\text{3+}}$ and ${\text{O}}^{2-}$ will give the compound structure as

Conclusion

The element Scandium will lose 3 electrons to form ${\text{Sc}}^{\text{3+}}$ and oxygen gains 2 electrons to form ${\text{O}}^{2-}$ and these will combine to give compound ${\text{Sc}}_2{\text{O}}_3$.