After a long search I’ve found that we can calculate g by this formula : g=m/I (The g-factor or gyromagnetic factor is the relation between the dipole magnetic moment (for an electric charged particle) and the angular momentum)
1.a) Ground state : m=-0.595 I = 1/2, thus g = -1.19
Excited state : m = -0.7663 I = 5/2 Thus g = – 0.306
1.b) m = 1mub and we know that electron has spin S=1/2
thus g=m/S = 2ml
1.c) g=-3.826 , m=g*S, we know the spin s = 1/2, thus
m = 1.913un (uN – nuclear magneton)