Answer:
88.76%
Step-by-step explanation:
Given that :
Half life of radium = 1599 years
Percentage that will remain after 275 years
Using the relation :
y = Ae^kt
Where ; A = mass of radium and t = half life = 1599, A = initial mass
By 1599, the mass of radium will be half its initial
Hence,
y = initial / 2 = A /2
A/2 = Ae^kt
To obtain the value of k
0.5 = e^1599k
In0.5 = 1599k
k = (In0.5)/1599
k = - 0.0004335
Hence,
y = Ae^-0.0004335t
Amount of radium. After 275 years : t = 275
y = Ae^-0.0004335*275
y = A0.8876191
y = 0.8876191 of intial amount
Hence, 0.8876191 * 100%
= 88.76%
