Question

Number of valence electrons in Chlorine ion are:
(a) 16
(b) 8
(c) 17
(d) 18

Answer 1

Hint: Chlorine is a chemical element with the atomic number 17 and the symbol Cl. It is the second-lightest of the halogens, appearing on the periodic table between fluorine and bromine, and its characteristics are largely midway between them. At room temperature, chlorine is a pale green gas with a yellow-green colour.

Complete answer:
A valence electron is an outer shell electron connected with an atom that can participate in the creation of a chemical bond if the outer shell is not closed; in a single covalent connection, both atoms contribute one valence electron to create a shared pair in chemistry and physics. The existence of valence electrons can affect an element's chemical characteristics, such as its valence—whether or not it can bind with other elements and, if so, how easily and how many times. In this sense, the reactivity of a particular element is strongly reliant on its electrical arrangement.
Valence electrons are electrons in the outer shells that are not completely filled. Chlorine has an atomic number of 17. Here is the electrical configuration of chlorine.
$$\mathbf{Cl}\left(\mathbf{Z}=\mathbf{17}\right)=\mathbf{1}{\mathbf{s}}^{\mathbf{2}}\mathbf{2}{\mathbf{s}}^{\mathbf{2}}\mathbf{2}{\mathbf{p}}^{\mathbf{6}}\mathbf{3}{\mathbf{s}}^{\mathbf{2}}\mathbf{3}{\mathbf{p}}^{\mathbf{5}}$$
 As a result, it possesses two electrons in its innermost shell, eight electrons in its second shell, and seven electrons in its outermost shell. As a result, the chlorine atom has seven valence electrons. The shell of the chlorine ion ($C{l}^{-}$) has 18 electrons. There are eight valence electrons in all.

Note:
A valence electron may receive or release energy in the form of a photon, much like a core electron. Atomic excitation occurs when an energy gain causes an electron to migrate (jump) to an outer shell. Alternatively, the electron can break free from its linked atom's shell, resulting in ionisation and the formation of a positive ion. When an electron loses energy (and so emits a photon), it might migrate to an inner shell that isn't completely occupied.