Chapter 7.1, Problem 1SSC

Interpretation Introduction

Interpretation: The stability of Lithium atom needs to be compared with ion, ${\text{Li}}^{+}$ .

Concept introduction:

All of the atoms tend to attain stable structure by losing electrons or gaining electrons to get a complete octet. In other words, all atoms follow octet rule which describes that the group elements will bond with other group elements in such a way that each atom will have eight electrons in its valence shell which is similar in configuration as noble gas.

Answer to Problem 1SSC

The Lithium ion is more stable than its atom as the Lithium ion has a complete octet.

Explanation of Solution

In order to compare the stability of Li atom with that of ${\text{Li}}^{+}$ ion, it is necessary to consider electronic configuration of the atom.

Li atom has atomic number 3. Its electronic configuration is 1s²2s¹. It can be seen that the inner shell is filled while the outer shell is half filled containing 1 electron.

  ${\text{Li}}^{+}$ ion will have only the inner two electron filled valence shell. The outer most electron is lost to become ${\text{Li}}^{+}$ ion. Hence now, the outer shell is 1s² and has electronic configuration of noble element He which is stable.

Comparing both the structures, it can be seen that Lithium ion is more stable than Li atom as it has a stable complete electronic configuration.

Conclusion

The Lithium ion is more stable than its atom as the Lithium ion has a complete octet.