This is a halogen element, lustrous solid, which volatilizing at ordinary temperatures into a blue-violet gas with an irritating odor. Ample amounts of this element are required by the human body for the proper function of the thyroid gland.
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 classified as an actinide and it is solid at room temperature. It is a synthetic transuranic element and can be produced in kilogram quantities. It is used in smoke detectors and as a portable source of gamma rays.