Question

A group of atoms carrying a charge is known as a:
A.Monatomic ion
B.Anion
C.Cation
D.Polyatomic ion

Answer 1

An atom consists of protons and electrons which subsequently denotes the charge on the atom. When an atom loses or gains electrons an ion is formed. The charge of the ion can be present on a single atom or the complete compound if they are bonded together.

Complete answer:
To find out the correct answer, let’s understand each term in the above-mentioned options.
Option A:
A Monatomic ion consists of only one atom because the word ‘mono’ means single or one. So this option is incorrect.
Option B:
An anion is a negatively charged ion. It deposits on the positively charged anode in the process of electrolysis. An anion is formed when an atom gains one or more electrons. So this option is incorrect.
Option C:
A Cation is a positively charged ion. It is attracted to the negatively charged cathode in electrolysis. A cation is formed as a result of the loss of one or more electrons from the atom. So this option is incorrect.
Option D:
In a polyatomic ion- ‘poly’ means many and ion denotes that it is carrying a charge. Thus, a polyatomic ion is an aggregation or group of two or more atoms having a charge on them. In the polyatomic ion, the groups are bonded to each other through covalent bonds. So they retain their charge and remain as a single bonded unit. Thus, this option is correct.
Final answer: The correct answer is Option D: Polyatomic ion.

Note:
Polyatomic ions form covalent bonds in the group, but they form ionic bonds with the other ion. So they can be referred to as ionic compounds. They react with acids and bases as a single unit. They also take part in displacement and precipitation reactions.