Gas-solid reactions occur when a gas interacts with a solid material, leading to a chemical change. These reactions are important in various fields, including catalysis, where solid catalysts facilitate reactions between gaseous reactants. The solid's surface area and reactivity significantly influence the reaction rate and efficiency. One common example of gas-solid reactions is the process of oxidation, where a gas like oxygen reacts with a solid substance, such as metal. This can lead to the formation of new compounds, like metal oxides, which are crucial in industries like metallurgy and materials science.