Question

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

Answer 1

`^(10)_5 B`
An atom of this isotope contains 5 protons and 10-5=5 neutrons.


`5 * 1.6726 * 10^(-27) + 5 * 1.6749 * 10^(-27) = \\ 8.363 * 10^(-27) + 8.3745 * 10^(-27)= \\ 16.7375 * 10^(-27)= \\ 1.67375 * 10^(-26) \approx \\ 1.67 * 10^(-26)`

The answer is A. 1.67 × 10⁻²⁶ kg.