Metal hydrides are compounds formed when metals react with hydrogen. They typically consist of a metal atom bonded to one or more hydrogen atoms. These compounds can be found in various forms, including ionic and covalent, and are used in applications such as hydrogen storage and batteries. Many metals, including lithium, sodium, and magnesium, can form hydrides. Metal hydrides are important in energy technologies, as they can absorb and release hydrogen gas, making them useful for fuel cells and other energy systems. Their ability to store hydrogen efficiently is a key factor in developing sustainable energy solutions.