Mandy's Candies is most famous for their homemade fudge and homemade toffee. They make an average of 151 pounds of fudge and toffee combined each month. They sell a pound of fudge for $8.34 and a pound of toffee for $7.67. Mandy's averages $1,202.39 each month in fudge and toffee sales. On average, how many pounds each of fudge and toffee does Mandy's Candies sell in one month?

a)

b) 3.15 weeks.

c) 0.11 grams

Step-by-step explanation:

a) radioactive decay follows first order kinetics and thus Expression for rate law for first order kinetics is given by:

where,

k = rate constant  = ?

t = time taken for decomposition = 1 week

a = initial amount of the reactant  = 1 g

a - x = amount left after decay process  = 0.8 g

Now put all the given values in above equation, we get

2) To calculate the half life, we use the formula :

Thus half life of Thorium 234 is 3.15 weeks.

3) amount of Thorium 234 present after 10 weeks:

Thus amount of Thorium 234 present after 10 weeks is 0.11 grams