Question

State the meaning of the term – (a) atom, (b) molecule, (c) radical – with a suitable example.

Answer 1

(a) Atom: It is the smallest particle of an element, which is made up of only one kind of atom. Atoms are built up of sub-atomic particles protons, neutrons, and electrons.

Example: O - Oxygen atom, H - Hydrogen atom

(b) Molecule: “The smallest particle of a substance which can exist on its own and retains the physical and chemical properties of the substance is called a molecule.”

Example: O₂ - Oxygen molecule, H₂O - Water molecule

(c) Radical: A radical is an atom of an element or a group of atoms of different elements that behaves as a single unit with a positive or negative charge on it.

Example: \[\ce{NH^+4}\] - Ammonium radical