Answer:
Explanation:
a )
m = m₀
m is mass after time t . original mass is m₀ , λ is disintegration constant
λ = .693 / half life
= .693 / 1590
= .0004358
m = m₀
b )
m = 50 x
= 40.21 mg .
c )
40 = 50
.8 =
= 1.25
.0004358 t = .22314
t = 512 years .