Inorganic compounds are substances that typically do not contain carbon-hydrogen (C-H) bonds. They can be classified into several types, including salts, minerals, and metals. Common examples include sodium chloride (table salt), calcium carbonate (found in limestone), and various metal oxides like iron oxide. Another category of inorganic compounds is acids and bases. Acids, such as sulfuric acid, release hydrogen ions (H⁺) in solution, while bases, like sodium hydroxide, produce hydroxide ions (OH⁻). These compounds play essential roles in chemical reactions, industrial processes, and biological systems.