WHAT IS AN ION?
Compounds composed of metals and non-metals contain charged species. The charged species are known as ions. Ions may consist of a single charged atom or a group of atoms that have a net charge on them. An ion can be negatively or positively charged.
CATION
The positively charged ion is called a ‘ cation ’. Take, for example, sodium chloride (NaCl). Its constituent particles are positively charged sodium ions (Na+).
ANION
A negatively charged ion is called an " anion ". Take, for example, sodium chloride (NaCl). Its constituent particles are negatively charged chloride ions (Cl–).
Source: This topic is taken from NCERT TEXTBOOK
POLYATOMIC ION
A group of atoms carrying a charge is known as a polyatomic ion (Table). We shall learn more about the formation of ions in Chapter 4.
Source: This topic is taken from NCERT TEXTBOOK