What is a molecule?

A molecule is defined as two or more atoms chemically bonded together. This definition encompasses a wide variety of structures, ranging from simple diatomic molecules like oxygen (O2) and nitrogen (N2) to more complex structures such as glucose (C6H12O6) or proteins made up of numerous atoms linked in specific arrangements. Each molecule retains its distinct chemical properties, which are often different from those of the individual atoms that compose it.

Molecules can be formed through various types of chemical bonds, including covalent bonds, where atoms share electrons, and ionic bonds, where atoms transfer electrons. This bonding process not only stabilizes the atoms but also allows them to interact in biological processes, materials science, and many other fields.

In contrast, a single atom refers to an indivisible unit of an element, a charged particle is essentially an ion, and elements on the periodic table represent pure substances that cannot be broken down into simpler substances by chemical means. Understanding the concept of molecules is fundamental in biology and chemistry because they are the building blocks of all living organisms and play crucial roles in cellular functions and biochemical reactions.