What is the relationship between atoms and molecules?

Atoms are the building blocks of matter, and molecules are formed when two or more atoms chemically bond together. The type and number of atoms in a molecule determine its properties and characteristics. Molecules can be composed of atoms of the same element, as in the case of diatomic molecules like oxygen (O2) and nitrogen (N2), or can be made up of different types of atoms, as in the case of water (H2O) and carbon dioxide (CO2). The way atoms are arranged and bonded together in a molecule determines its shape, size, and reactivity. The study of atoms and molecules is an essential part of chemistry and is key to understanding the behaviors and interactions of substances in the physical world.