Are selenium aluminium carbon metalloids?

Selenium is less commonly recognised as a metalloid and is more often counted as a nonmetal; carbon (notionally a nonmetal) and aluminium (notionally a metal) are rarely recognised as metalloids. read more

Carbon, aluminium, phosphorus and selenium continue the theme. Carbon, in black powder, is a constituent of fireworks rocket propellants, bursting charges, and effects mixtures, and military delay fuses and igniters. read more

Wikipedia has a list of 192 metalloid lists, and selenium is shown as a metalloid in 24% of those lists: Lists of metalloids - Wikipedia Selenium shows borderline metalloid or nonmetal behaviour. Its most stable form, the grey trigonal allotrope, is sometimes called "metallic" selenium because its electrical conductivity is several orders of magnitude greater than that of the red monoclinic form. read more