ATOMIC number is 6 then its electronic configuration is 2,4 .So its valency is 4

Valency is a measure of an element's ability to combine with other elements and form chemical compounds. It represents the number of electrons an atom can gain, lose, or share to achieve a stable outer electron configuration, usually in the form of eight valence electrons.

In this case, we are given that the element has a valency of Z = 6. To understand the valency of the element, we need to consider the electronic configuration of the element's outermost shell.

The electronic configuration of an element is represented by a series of numbers and letters. The first number represents the energy level or shell, and the letter represents the type of subshell (s, p, d, or f). The second number represents the number of electrons in that subshell.

In general, the valency of an element is determined by the number of electrons in its outermost shell. This can be calculated using the formula:

Valency = 8 - (number of electrons in the outermost shell)

Now, let's apply this formula to the given valency of Z = 6.

Number of electrons in the outermost shell = 8 - Valency

Number of electrons in the outermost shell = 8 - 6 = 2

Therefore, the element has 2 electrons in its outermost shell. This corresponds to the electronic configuration of a s2 subshell.

The valency of an element with a s2 subshell is usually 2, as it can either lose its two outermost electrons or gain six more electrons to achieve a stable configuration. However, it is important to note that the valency of an element can vary depending on the specific compound or reaction it is involved in.

Therefore, the correct answer is option 'C', which states that the valency of the element is 4.