Molecular behavior refers to how molecules interact with each other and their environment. This includes movements, collisions, and changes in energy. Molecules are constantly in motion, and their speed and arrangement can change based on temperature and pressure. For example, in a gas, molecules move freely and quickly, while in a solid, they are closely packed and vibrate in place. The behavior of molecules is influenced by forces such as hydrogen bonds, van der Waals forces, and ionic interactions. These forces determine properties like boiling points, melting points, and solubility. Understanding molecular behavior is essential in fields like chemistry and biochemistry, where it helps explain reactions and the formation of new substances.