What is the expected mass (in kg) of a 10 over 5 b isotope? 1 proton = 1.6726 × 10-27 kg 1 neutron = 1.6749 × 10-27 kg a.1.67 × 10-26 kg b.1.67 × 1026 kg c.2.51 × 10-26 kg d.2.51 × 1026 kg