Question

The most non-metallic element among the following is:
(A) S
(B) P
(C) O
(D) Cl

Answer 1

Nonmetals have a greater number of valence electrons and they increase their stability by gaining electrons or by becoming anions. The nonmetals will have a higher electronegativity and thus by finding the most electronegative element in the options we could find the element with the most non-metallic nature.

Complete step by step solution:
-As we are aware, elements in the periodic table are further classified into metals, non-metals, and metalloids based on their properties. In the leftmost part of the periodic table, metallic character is strongest for the elements and tends to decrease as we move to the right in any period and within a group of elements, from top to bottom the metallic character will increase.
- Let's see in detail about nonmetals. They are the elements which form negative ions by gaining or by accepting electrons. They normally have four to seven electrons in their outermost shell.
- In comparison with metals they lack all the metallic attributes and they usually act as good insulators of electricity and heat. Nonmetals are sometimes liquid and mostly gases. Some of them are even solid like Phosphorus, Carbon and Sulphur at room temperatures.
- Nonmetallic character of an element can be directly attributed to electronegativity. As we know, electronegativity is the measure of attraction of an atom towards electrons. Hence the greater attraction for bonding electrons, higher would be the electronegativity of an atom.
-The property electronegativity is directly related to ionization energy of the atom. Those electrons which has low ionization energies will have low electronegativities because of the fact that their nuclei do not exert a strong attractive force on the electrons. Or in other words, the elements with high ionization energies will have high electronegativities due to the higher pull exerted on the electrons by the nucleus.
- As a result of the increased distance between the nucleus and valence electron (greater atomic radius) in a group, the electronegativity will decrease as the atomic number increases. Therefore, halogens will have the highest electronegativity. Among the given options chlorine is the halogen and it would be the most non-metallic element.

Therefore, the answer is option (D) Chlorine.

Note: The answer can also be found in a simple way. If we go from left to right across the periods in the periodic table, nonmetallic character also increases as a result of increase in ionization energy. Among the given options the element chlorine is the element which is on extreme right. Thus, it would have a higher non metallic nature.