question_answer

Calculate the approximate charge in coulombs and approximate mass in kilograms of the nucleus of lithium-7 isotope.

Answer:

                Nucleus of Li atom has 3 protons and 4 neutrons. Charge on one proton \[=1.60\times {{10}^{-19}}\] coulombs \[\therefore \] Charge on 3 protons (i.e., charge on nucleus) \[=3\times 1.60\times {{10}^{-19}}C=4.80\times {{10}^{-19}}C\]Mass of proton \[\approx \] mass of neutron \[\approx \,1.67\times {{10}^{-27}}\,kg\] \[\therefore \] Mass of nucleus \[=7\times 1.67\times {{10}^{-27}}\,kg=11.69\times {{10}^{-27}}\,kg\]