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.
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.