<Tr> <Td> charm </Td> <Td> </Td> <Td> ​ ⁄ </Td> <Td> + ​ ⁄ </Td> <Td> 1160 to 1340 </Td> <Td> ~ 1 proton </Td> <Td> anticharm </Td> <Td> </Td> </Tr> <Tr> <Td> top </Td> <Td> </Td> <Td> ​ ⁄ </Td> <Td> + ​ ⁄ </Td> <Td> 169,100 to 173,300 </Td> <Td> ~ 180 protons or ~ 1 tungsten atom </Td> <Td> antitop </Td> <Td> </Td> </Tr> <Tr> <Td_colspan="7"> down - type quarks </Td> </Tr> <Tr> <Td> down </Td> <Td> d </Td> <Td> ​ ⁄ </Td> <Td> − ​ ⁄ </Td> <Td> 3.5 to 6.0 </Td> <Td> ~ 10 electrons </Td> <Td> antidown </Td> <Td> d </Td> </Tr>

A type of matter in which all the atoms are the same