Question

An atom or group of atoms of the same or of different elements that behaves as a single unit with a positive or negative charge is known as:
A.Radical
B.Valency
C.Clusters
D.None of the above

Answer 1

First of all, we will see which option has an unpaired electron, but does not have a net charge because the number of protons equals the number of electrons. They are formed as compulsory intermediates in different normal biochemical reactions, but when generated in excess or not properly controlled.

Complete step by step answer:
An atom is the smallest particle of an element that takes part in a chemical reaction and a molecule is an electrically neutral group of two or more atoms chemically bonded together. Molecules are of two types. The two types of molecules are:
a)molecule of an element
b)molecule of an elopement containing the same type of atoms.
A radical is an atom or a group of atoms of the same or different elements that acts as a single unit and has a positive or negative charge. It has definite valency and definite chemical formula. When sums and differences are under a radical sign, they cannot be split into separate radicals. Valency is the combining capacity of an element. The numbers of electrons present in the outermost shell of an atom are called valence electrons.
Thus, we know that an atom or a group of atoms of the same or of different elements which behaves as a single unit with a positive or negative charge is known as radical.

Therefore, the correct answer is option (A).

Note: Radicals are of two types: Positive radicals or Cations and Negative radicals or Anions. Positively charged radicals are called basic radicals such as $N{a^ + },N{H_4}^ +$ etc. Negatively charged radicals are called acidic radicals like $N{O_3}^ - ,C{l^ - }$, etc.