1a- using the formula in the video and the values for the nuclear magneton and h bar, as well as the values in that website:
g_ground=-2.48×10^(-17)
g_245 keV=-4.19×10^(-18)
1b- using again the formula and the knows values for the mass and charge of the electron, as well as spin -1/2:
g_elec=-2.27×10^(-17)
1c- using the values i get mu_n=-91679160 which doesn’t seem right with the order of magnitude, i must have used a worng value or something