The key difference between an atom and a molecule lies in their composition and structure:
- An atom is the smallest unit of an element that retains all the chemical properties of that element. It consists of a nucleus made of protons and neutrons, surrounded by electrons in orbitals. Atoms are the fundamental building blocks of matter and cannot be broken down into simpler substances by ordinary chemical means
- A molecule is formed when two or more atoms chemically bond together. These atoms can be of the same element (e.g., O₂, oxygen gas) or different elements (e.g., H₂O, water). Molecules represent the smallest unit of a compound that retains the chemical properties of that compound
In summary:
- Atom: Single unit of an element; smallest particle with element properties.
- Molecule: Two or more atoms bonded together; smallest unit of a compound or element molecule.
This means atoms are like individual building blocks, while molecules are structures built from those blocks chemically joined
. Thus, an atom is a single particle, whereas a molecule is a group of atoms bonded together.
