This is a non-metal and it is a structural element of all biomolecules and living beings. Three naturally occurring allotropes of this element are known to exist: amorphous, graphite and diamond.
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.