Nonmetal are called "metalloids" mainly in light of their physical resemblance to metals. While they each have a metallic appearance, they are brittle and only fair conductors of electricity. Boron, silicon, germanium, tellurium are semiconductors. Arsenic and antimony have the electronic band structures of semimetals although both have less stable semiconducting allotropes. Astatine has been predicted to have a metallic crystalline structure. Chemically the metalloids generally behave like (weak) nonmetals. They have moderate ionisation energies, low to high electron affinities, moderate electronegativity values, are poor to moderately strong oxidising agents, and demonstrate a tendency to form alloys with metals. The reactive
Minor metals 40 percent of all production, but that China's share of global production increased 34 percent between 2000 and 2009. Minor metals are used in a wide diversity of end-use applications, from capacitors for consumer electronics (tantalum) and metallic cathodes for rechargeable batteries (cobalt) to photovoltaic solar cells (silicon) and semiconductor materials (gallium and indium).The primary end-uses of minor metals can also help to categorize the metals into four groups: Metals often classified as minor metals include: Antimony (Sb), Arsenic (As), Beryllium (Be), Bismuth (Bi), Cadmium (Cd), Cerium (Ce), Chromium (Cr), Cobalt (Co), Gadolinium (Gd), Gallium (Ga), Germanium (Ge), Hafnium (Hf),