Question

The most non-metallic element is:
(A) Na
(B) He
(C) Cl
(D) F

Answer 1

Hint: In the "periodic table", all elements are placed in increasing order of their atomic number. If we check the periodic table, according to metallic and non-metallic nature, the left side of the periodic table contains metals whereas the right side contains non-metals.

Complete step by step solution:

Metallic character of an element is defined as the tendency of the element to lose electrons and form cations. It is also commonly called electropositivity. Most electropositive elements are Alkali metals.
Non-metallic character of an element is defined as the tendency of the element to accept electrons to form an anion. It is also called electronegativity. Chlorine, oxygen and phosphorus are some of the examples of metals which show greater electronegative or non-metallic character.

Factors that affect metallic and non-metallic characters of an element are:
• Size of an atom
• Ionization enthalpy
• Nuclear charge

Most reactive nonmetals are placed in the upper right-hand part of the modern periodic table. Since the noble gases are a special group because they show very less reactivity, the element fluorine is the most reactive nonmetal, which is the reason it is not found in nature as a free element. It reacts violently with many other elements and compounds and is considered to be one of the most dangerous known substances.

So, the correct option is (d).

Note: As discussed Fluorine is the most chemically reactive and electronegative of all the elements. It forms compounds even with the noble gases’ krypton, xenon and radon. This can alone illustrate how reactive it is.