is carbon a metal nonmetal or a metalloid

Carbon is classified as a nonmetal. It is an essential element found in all known life forms and is the basis for organic chemistry. Carbon has several allotropes, including graphite, diamond, and graphene, each with distinct physical properties. 

In its various forms, carbon exhibits different characteristics. For instance, graphite is a good conductor of electricity and is soft and slippery, whereas diamond is an extremely hard material with excellent insulating properties. Despite these variations, carbon's fundamental chemical behavior classifies it firmly as a nonmetal.