Find (i) the total number and (ii) the total mass of neutrons in 7 mg of `_^14C` (Mass of neutron `=1.675xx10^(-27)kg`)

If wavelength of neutron beam used in neutron microscope is 800 pm, calculate the velocity associated with the neutron (Mass of neutron 1.675xx10^(-27)kg )

Calculate the wavelength (in nanometer) associated with a proton moving at 1.0xx10^(3) ms^(-1)s (mass of proton = 1.67 xx 10^(-27) kg and h = 6.63 xx 10^(-34) Js)

Cyclotron Is a device which accelerates charged particles for carrying out nuclear reactions. Find the energy of emergent protons.(in MeV) coming from a cyclotron having dees of radius 2 metres, when a magnetic field of 0.8 T Is applied. (Mass of proton =1.67xx10^-27 kg)

A cyclotron.s oscillator frequency is (10 MH_z) ,. What should be the operating magnetic field for accelerating protons ? [C = 1.6 x 10^(-19)] C, mass of proton [n_p = 1.67 x 10^(-27)] kg.

Is there any relation between the total number of protons and neutrons in an atom and its mass?