Correct option : (2) 1.0089992 + 0.000003 amu
Explanation:
The mass of neutron is given by
= –0015380 + 1.008145 – 0.002392 = 1.0089999 amu
Errors:
(i) Energy 2.27 ± 0.003 MeV equivalent of an error of 0.000003
(ii) Doublet error = ± 0.0000021 amu
(iii) Hydrogen atom = 0.00003 amu
Total maximum error is ± 0.000008 amu
Hence the mass of neutron is 1.0089992 ± 0.000008 amu