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 is a non-metal and the most abundant element in the Universe. It is the basic fuel for nuclear reactions in the stars. It is a gaseous substance on Earth and the lightest element in the Universe.
This element and its compounds are poisonous and they are used for the production of rat poison and insecticides. It is a metalloid. Small amounts of this element are added to germanium to make transistors.