Chemical behaviours refer to the various reactions and interactions that occur between different substances. These behaviours include combustion, where a substance reacts with oxygen to produce heat and light; decomposition, where a compound breaks down into simpler substances; neutralisation, where an acid and a base react to form water and a salt; precipitation, where two solutions react to form an insoluble solid; redox reactions, which involve the transfer of electrons between substances; synthesis, where two or more substances combine to form a new compound; double displacement, where two compounds exchange ions to form new compounds; and the functioning of chemical cells, including galvanic and electrolytic cells. Understanding these chemical behaviours is essential for studying chemistry and its applications in various fields, such as energy production, materials science, and environmental science.