Question

The combining capacity of an element is known as its ________.

Answer 1

Hint: The combining capacity of an element will tell you the number of atoms that are bonded to the given atom. Thus, if you count the number of bonds around the central atom, you can determine its combining capacity.

Complete answer:
The combining capacity of an element is dependent upon the number of electrons needed by an atom to achieve stable electronic configuration.
The combining capacity of an element is known as its valency.
For a nonmetal, you can calculate its valence by subtracting the number of valence electrons from 8. The valence electrons are the number of electrons present in the outermost shell. The outermost shell is also called the valence shell.
Thus, chlorine has 7 valence electrons. So, its valence will be 8 - 7 = 1. To attain stability, chlorine gains one valence electron and completes its octet. In this way, it attains stability. Similarly, oxygen has 6 valence electrons. So, its valence will be 8 - 6 = 2. To attain stability, oxygen gains two valence electrons and completes its octet. In this way, it attains stability.
For metals, you can calculate the valence from its valence shell electronic configuration. For example, sodium has only one electron in its valence shell. So, its valence is one. To attain stability, sodium loses one valence electron and completes its octet. In this way, it attains stability. On the other hand, magnesium has two electrons. So, the valence of magnesium is two. To attain stability, magnesium loses two valence electrons and completes its octet. In this way, it attains stability.

So the combining capacity of an element is known as its valency.

Note: The valency of an atom represents the number of bonds it can form with other atoms. For example, in methane \[{\text{C}}{{\text{H}}_4}\] molecules, carbon atoms form a total of four bonds with four hydrogen atoms. Hence, the valence of carbon is 4.