Question

Neptunium 239
93 Np has a decay constant of 3.40 ×10-6 s-1. A 3.0-mg sample of Np-239 is
prepared. The activity of the Np-239 sample, in Ci, is

Answer 1

activity=dN/dt=3.4E-6*3grams/239 *avagradros number.