A molecule is the smallest unit of a substance that retains all its chemical and physical properties. It consists of two or more atoms that are chemically bonded together. These atoms may be of the same element or different elements. Molecules can be simple, like oxygen (O2), which consists of two oxygen atoms, or complex, like water (H2O), which consists of hydrogen and oxygen atoms chemically combined. Molecules form when atoms bond to achieve stability, typically by sharing or transferring electrons to complete their outer electron shells. This bonding makes the molecule more stable and less reactive than the individual atoms alone. Molecules can be categorized as homonuclear if they consist of atoms of the same element, or heteronuclear if they contain atoms of different elements. In summary:
- A molecule is an electrically neutral group of two or more atoms held together by chemical bonds.
- It is the smallest particle of a substance that retains that substance's chemical and physical properties.
- Examples include oxygen (O2), water (H2O), and glucose (C6H12O6).
Thus, molecules are fundamental building blocks of matter and are essential in both chemistry and biology.
