A piece of radium has an activity of 16 mCi a What is the ma

A piece of radium has an activity of 16 mCi.

(a) What is the mass of the radium?

(b) What is its activity in Bq?

m = M*N/A N is disintigration constant for radium 226 is N = 1.35*10^-11 s-1,4 M is 226

from rater of disintigration is given by

dN/dt = K*(m/M)*A

16*10^-3*3.7*10^10 = 1.35*10^-11(m/226)(6.02*10^23)
m = 16.462 grams

mass of radium is 16.462 g

b) we know that one Ci = 3.7*10^10 Bq => 16 mCi = 16*10^-3*3.7*10^10 = 5.92*10^9 Bq