This element is classified as a lanthanide and it is the most abundant of the rare-earth elements of the earth’s crust. It is the most reactive of the rare-earth metals and is used as a catalyst to refine petroleum.
This element is a transition metal used in large amounts by the electrical industry in the form of wire. This metal is the second-best in the electrical conductance. Because this element resists corrosion in air, moisture and seawater, it has been widely used in coins.
This element is a noble gas which is gas at room temperature. It is characterized by its brilliant green and orange spectral lines. This noble gas is used in fluorescent light bulbs, luminous signs, high-speed photography.