Question

What is the smallest particle of a compound?

Answer 1

A compound is a unique substance in which two or more elements are present that are combined in fixed proportion. The composition of a compound is always found to be the same. The smallest particles of a compound have independent existences and that can retain all the properties of that compound.

Complete answer:
A compound is a unique substance which consists of two or more elements in fixed proportions. This will indicate that the composition of a compound is always found to be the same. The smallest particle of the compound is a molecule.
A molecule is defined as the group of atoms held together by specific chemical bonds. A chemical bond is a force that holds together the atoms in a molecule. It is electrically neutral. It is capable of an independent existence and shows all the properties of that substance. Molecules are differentiated from the ions due to the lack of electrical charges.
The statement of a molecule in a compound is related to the statement of an atom in an element. Element is the pure substance. It cannot be broken into substances. The atom is the smallest particle of an element that can exist independently and retain the properties of that element. Similarly, the molecule is the smallest particle of a compound that exists independently and retains the properties of that compound.

Note :
Molecules are held together by specific chemical bonds. These bonding can either covalent bonding or ionic bonding. Some non-metal elements exist as molecules only. For example- hydrogen exists as a molecule only.