The key difference between atom and molecule is that an atom is the smallest unit of an element, while a molecule is a group of atoms chemically bonded together.
Atom vs Molecule
The major difference between atom and molecule is given below:
| Atom | Molecule | |
| Composition | The basic unit of matter, consists of a nucleus (protons and neutrons) and electrons. | Consists of two or more atoms chemically bonded together. |
| Examples | Oxygen atom (O), Hydrogen atom (H). | Oxygen molecule (O2), Water molecule (H2O). |
| Formation | Atoms combine to form molecules through chemical bonding. | Molecules result from the bonding of atoms to achieve stability. |
| Properties | Atoms retain their element’s properties. | Molecules have distinct chemical properties from the atoms they’re composed of. |
| Stability | Atoms seek to achieve a stable electron configuration. | Molecules form to achieve a more stable state by sharing or transferring electrons. |
| Chemical Behavior | Participate in chemical reactions as individual units. | Undergo chemical reactions as entities with combined properties. |
| Size | Atoms are the smallest units of elements. | Molecules can vary in size, composed of multiple atoms. |
| Representation | Usually represented by elemental symbols (e.g., C for carbon). | Represented by chemical formulas indicating the types and numbers of atoms (e.g., H2O for water). |
| Bonding | Atoms can form bonds to create molecules or compounds. | Molecules consist of bonded atoms, connected by covalent or other types of bonds. |
What is Atom?
An atom is the fundamental unit of matter, composed of a central nucleus containing positively charged protons and neutral neutrons, surrounded by negatively charged electrons.
Atoms are the building blocks of all elements and are characterized by their unique number of protons, known as the atomic number, which defines the element’s identity. The arrangement and interactions of atoms give rise to the diverse properties and behaviors of different substances in the universe.
What is Molecule?
A molecule is a group of two or more atoms that are chemically bonded together. These atoms can be of the same element or different elements. Molecules are the smallest units of compounds and substances formed through chemical reactions.
They can be simple, consisting of just a few atoms, or complex, containing many atoms. The arrangement and types of atoms within a molecule determine its chemical properties and behavior, contributing to the diversity of substances in the world.