The Lewis symbol, also known as the Lewis dot structure or electron dot structure, is a representation of the valence electrons in an atom. It uses dots to represent the valence electrons and indicates the number of valence electrons an atom has.

The options provided in the question are:

a) electrovalency
b) group valence of the element
c) the number of valence electrons of the element
d) coordinate valency

The correct answer is option 'C', which states that the number of dots around the Lewis symbol represents the number of valence electrons of the element. Let's discuss why this is the correct answer in detail.

Understanding Valence Electrons:
Valence electrons are the electrons located in the outermost energy level or shell of an atom. These electrons are involved in bonding with other atoms to form compounds. The number of valence electrons determines the chemical properties of an element.

Explanation of the Correct Answer:
The Lewis symbol represents the valence electrons of an element. Each dot in the Lewis symbol represents one valence electron. The number of dots around the symbol corresponds to the number of valence electrons an element possesses.

For example, let's consider the Lewis symbol for oxygen, which has 6 valence electrons. The symbol for oxygen is represented as 'O', and the Lewis symbol would have 6 dots surrounding the symbol. Each dot represents one valence electron, and the 6 dots indicate the 6 valence electrons of oxygen.

By counting the number of dots in the Lewis symbol, we can determine the number of valence electrons for a given element. This information is crucial in understanding the chemical behavior and bonding patterns of elements.

Other Options:
a) Electrovalency refers to the valency of an atom or ion in an ionic compound. It is not directly related to the number of dots around the Lewis symbol.
b) Group valence of the element refers to the number of valence electrons an element has based on its group number on the periodic table. While this can give an idea of the number of valence electrons, it is not directly related to the number of dots around the Lewis symbol.
d) Coordinate valency is a term used in coordination compounds to describe the number of ligands that can coordinate with a central metal ion. It is not related to the number of dots around the Lewis symbol.

In conclusion, the number of dots around the Lewis symbol represents the number of valence electrons of the element. Each dot corresponds to one valence electron, and by counting the dots, we can determine the number of valence electrons an element possesses.