The half-life of 131I is 8.04 days. Three days after it was ...

[D2AR0N]

The half-life of 131I is 8.04 days. Three days after it was prepared, its activity was 0.50 mCi. How many curies (in mCi) were initially prepared?
 a. .60
  b. .70
  c. .65
  d. .55
  e. .39

Question 2

44 g of petrified wood was found in a petrified forest. A sample showed a 14C activity of 100 decays/minute. How long has the tree been dead (in years)? (The half-life of carbon-14 is 5730 years and freshly cut wood contains 6.5  1010 atoms of 14C per gram.)
 a. 12 300
  b. 15 600
  c. 8 500
  d. 4 700
  e. 2 400

[skipfourms123]

Answer to Question 1

C

Answer to Question 2

B

[D2AR0N]

TYSM

[okolip]

Gracias!