Metals do burn. In fact, most metals release a lot of heat when they burn and are hard to put out. For example, thermite is used to weld train rails together. The fuel in thermite is the metal aluminum. When thermite burns, the aluminum atoms bond with oxygen atoms to form aluminum oxide, releasing a lot of heat and light in the process. As another example, hand-held sparklers use aluminum, magnesium, or iron as the fuel. The flame of a sparkler looks different from the flame of a wood fire because metal tends to burn hotter, quicker, and more completely than wood. This is what gives a lit sparkler its distinctive sparkling flame. In fact, most fireworks contain metal fuels. As another example, old flash tubes used in photography were nothing more than burning bits of magnesium in a glass bulb. Also, the space shuttle's solid rocket boosters used aluminum as the fuel. Some metals, such as sodium, burn so well that we don't make everyday objects out of them. Any boy scout who has started a fire using steel wool can attest to the fact that metals burn.