This is a transition metal. This is a metal of the platinum family and it is the most corrosion-resistant metal known. It is used in the production of the alloys with osmium and platinum and in the production of crucibles and devices requiring high temperatures.
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 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.