Particle Mass (amu) proton 1.007593 neutron 1.008982 deuterium 2.014186 tritium 3.016448 helium 3 3.015779 helium 4 4.003873 1.0 ev = 1.6 · 10-19 j 1.0 amu = 931 Mev 1 angstrom () = 1 X 10-10m h = 6.63 · 10-34 J-s. Always use significant figure rules. Remember that these rules apply to all numbers that are measurements. Calculate the wavelength of radiation emitted when a hydrogen electron jumps from the -1.5 ev energy level to the -3.4 ev energy level. = 0.9. 6600 10470 1900