Chapter 18.1, Problem 1R

To determine

To explain:The reason some elements are stable on their own while others are more stable in compounds.

Explanation of Solution

Introduction:

The elements which have their outermost shell incomplete are not said to be stable on their own. Those elements which rather have their outermost shell completed or full fill are called as stable on their own.

The elements which belong to the groups such as 1, 2, 13,14,15, 16,17 and 18 have incomplete outermost shell such as group 1 have 1 electron,group 2 have 2 electrons, group 13 have 3 electrons,group 14 have 4 electrons,group 15 have 5 electrons,group 16 have 6 electrons,group 17 have 7 electrons and group 18 have 8 electrons.

Hydrogen and helium are two such elements that can have maximum of 2 electrons in their outermost shell. It is called duplet and the remaining element tends to have 8 electrons in their outermost shell which are called an octet. Thus, all elements which don’t have their outermost shell completely filled with electrons are not stable on their own but can form compounds with other elements.

On the other hand, the elements having their duplet or octet completely filled with electrons are more stable on their own and don’t form a compound with other elements.

Conclusion:

Hence,those elements which have incomplete outermost shell are not stable on their own but which have full filled outermost shell are stable.