An element is a substance that cannot be broken down into a simpler substance by any known means. Each of the 92 naturally occurring elements is therefore one of the fundamental materials from which everything in the universe is made. The element, Aluminum is the third most common element on Earth after Oxygen and Silicon. Also by far the most abundant metal on Earth, is now used very widely for everything from soft-drink cans to car bodies to window frames. Around 8 percent of Earth's outer layer (crust) is made up of aluminum. Compounds containing aluminum are found in materials as different as antacid medicines, the insulation material in our homes, and in the small white flecks (called vermiculite) in garden composts.
             Aluminum is a shiny, silvery metal. It is extremely light and so soft that a thick sheet can be bent easily by hand. When exposed to the air, the surface of the metal reacts with oxygen to form an aluminum oxide, coating, preventing further corrosion of the metal underneath. Also, aluminum have weak metals (like copper and tin) that scientists call "poor" metals. But aluminum alloys, mixtures of aluminum and other metals, produce materials as tough as steel. All these properties make aluminum a very important element. It uses range from making chewing gum wrappers and beverage cans to armor plating for tanks and airplane bodies. Indeed, the modern world would be a very different place without aluminum.
             Every atom contains even smaller particles called protons, neutrons, and electrons. The protons and neutrons cluster together in the nucleus at the center of an atom. The electrons spin around the nucleus in a series of layer called electron shells. The number of protons is given by the atomic number. Aluminum has an atomic number of 13, so there are 13 protons in each atom. The protons and neutrons combine to give the atom its mass. Aluminum has an atomic mass of 27, which means each atom has 14...