<Table> Electron <Tr> <Td_colspan="2"> Hydrogen atom orbitals at different energy levels . The brighter areas are where one is most likely to find an electron at any given time . </Td> </Tr> <Tr> <Th> Composition </Th> <Td> Elementary particle </Td> </Tr> <Tr> <Th> Statistics </Th> <Td> Fermionic </Td> </Tr> <Tr> <Th> Generation </Th> <Td> First </Td> </Tr> <Tr> <Th> Interactions </Th> <Td> Gravity, electromagnetic, weak </Td> </Tr> <Tr> <Th> Symbol </Th> <Td>, β </Td> </Tr> <Tr> <Th> Antiparticle </Th> <Td> Positron (also called antielectron) </Td> </Tr> <Tr> <Th> Theorized </Th> <Td> Richard Laming (1838--1851), G. Johnstone Stoney (1874) and others . </Td> </Tr> <Tr> <Th> Discovered </Th> <Td> J.J. Thomson (1897) </Td> </Tr> <Tr> <Th> Mass </Th> <Td> 6969910938355999999 ♠ 9.109 383 56 (11) × 10 kg 6996548579909069999 ♠ 5.485 799 090 70 (16) × 10 u (7003182288848450000 ♠ 1822. 888 4845 (14)) u 6999510998946099999 ♠ 0.510 998 9461 (31) MeV / c </Td> </Tr> <Tr> <Th> Mean lifetime </Th> <Td> stable (> 7036208280160000000 ♠ 6.6 × 10 yr) </Td> </Tr> <Tr> <Th> Electric charge </Th> <Td> 3018839782351300000 ♠ − 1 e 3018839782337920000 ♠ − 1.602 176 6208 (98) × 10 C 3009519679549000000 ♠ − 4.803 204 51 (10) × 10 esu </Td> </Tr> <Tr> <Th> Magnetic moment </Th> <Td> − 1.001 159 652 180 91 (26) μ </Td> </Tr> <Tr> <Th> Spin </Th> <Td> 1 / 2 </Td> </Tr> <Tr> <Th> Weak isospin </Th> <Td> LH: − 1 / 2, RH: 0 </Td> </Tr> <Tr> <Th> Weak hypercharge </Th> <Td> LH: - 1, RH: − 2 </Td> </Tr> </Table> <Tr> <Td_colspan="2"> Hydrogen atom orbitals at different energy levels . The brighter areas are where one is most likely to find an electron at any given time . </Td> </Tr>

What is the exact mass of an electron