Chapter 7, Problem 66A

Interpretation Introduction

Interpretation:

The reason for compound formed between Barium and Iodine to not be BaI needs to be determined.

Concept introduction:

Molecules are bound together by different types of bonds namely ionic and covalent. 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 causes the ionic bond formation.

Answer to Problem 66A

The compound formed between Barium and Iodine is not BaI as it is not electrically neutral.

Explanation of Solution

Ionic bonds involve the transfer of electrons from one atom to the other. The metal atoms, an electrons donor, loses electrons to form a positively charged ion while the non-metal atoms, electron acceptor, gains electrons to form negatively charged ions. During the process of donating or gaining electrons, the atoms follow octet rule to attain a stable noble gas configuration. Therefore, the charges on the anion and cation depends on the electrons lost or gained giving net charge of zero.

Barium has atomic number of 56 with electronic configuration as $\left[\text{Xe}\right]{\text{ 6s}}^2$. There are two outermost electrons which barium will lose to form a Barium ion, ${\text{Ba}}^{\text{2+}}$.

Iodine has atomic number of 53 with electronic configuration as $\left[\text{Kr }\right]{\text{ 4d}}^{10}{\text{5s}}^2{\text{5p}}^5$. It has 7 valence electrons and requires 1 more electron to get octet structure. If a compound is to be formed between Barium and Iodine, one ion from Barium is sufficient to fulfill Iodine vacancy. Thus, the compound BaI is not electrically neutral. To form compound Ba needs 2 I atoms.

This results in the formation of BaI₂. Thus, BaI is not formed.

Conclusion

Compound BaI from Barium and Iodine cannot be formed because it is not electrically neutral.