Cobalt-60 has a half-life of about 5 years. how many grams of 300 g sample well remain after 20 years?

After 20 years 18.75 gm of sample will remain.

Step-by-step explanation:

This is the case of an exponential decay of Cobalt-60. The function for exponential decay is,

where,

y(t) = amount left after time t  

a = initial amount = 300 g

r = rate of decay = 0.5 (as the sample is getting halved each time)

t = number of periods = (as we have to convert the period in terms of half lives)

Putting the values,

according to egenuity the answer is

step-by-step explanation:

d. 344.22