Question

A smallest particle of a compound that can have the independent existence and that can retain all the properties of that compound is called as:
A. Molecule
B. Ion
C. Atom
D. Element

Answer 1

Hint: A molecule is an electrically neutral group of two or more atoms held together by specific chemical bonds. Molecules are distinguished from ions by their lack of electrical charge. In the kinetic theory of gases, the term molecule is often used for any gaseous particle regardless of its composition.

Complete step by step answer:
A molecule can be defined as the smallest particle of an element or a compound that is capable of an independent existence and shows all the properties of that substance. Molecular chemistry deals with the laws governing the interaction between molecules that result in the formation and breakage of chemical bonds, while molecular physics deals with the laws governing their structure and properties. In practice, however, this distinction is vague. In molecular sciences, a molecule consists of a stable system (bound state) composed of two or more atoms. Polyatomic ions may sometimes be usefully thought of as electrically charged molecules. The term unstable molecule is used for very reactive species, i.e., short-lived assemblies (resonances) of electrons and nuclei, such as radicals, molecular ions, etc.
Although the statement of a molecule is related to a compound, it can also be related to the statement of an atom which states that the atom is the smallest particle of an element that has an independent existence and can retain the properties of that element.

Thus, the correct option is A. molecule.

Note:
Molecules are held together by either covalent bonding or ionic bonding. Several types of non-metal elements exist only as molecules in the environment. For example, hydrogen only exists as a hydrogen molecule. A molecule of a compound is made out of two or more elements.