The halflife of dubnium261 is 27 seconds If there are 36 gra
     The half-life of dubnium-261 is 27 seconds. If there are 36 grams present initially, write a function that gives the amount remaining as a function of time. 
  
  Solution
half life of dubnium -261 = 27 seconds
initial amount = 36 grams
standard equation of exponential function is
P = Po e^kt
where , P = final amount
Po = initial amount
t = time
k = growth/decay constant
plugging the values in exponetial equation
18 = 36 e^k(27)
dividing equation by 36
1/2 = e^k(27)
taking ln on both sides
ln (1/2) = 27 k ln e
-.69314 = 27 k
k = -.0256
therefore, function would be
P = 36 e^(-.0256 t )

