An old bone sample contains 321 g of carbon and has an activity ...

[nenivikky]

An old bone sample contains 321 g of carbon and has an activity of 947 decays/min due to the carbon-14 in it. The half-life of carbon-14 is 5730 y.
 
  Assume that the activity of the atmospheric carbon is, and has remained, 0.255 Bq per gram of carbon.
  (a) How old is the sample?
  (b) What will be the activity of the sample 2000 y from now, in decays per minute?

Question 2

If you confine an electron to a box and know that the uncertainty in the electron's speed is 65 m/s,
 
  what is the smallest length that the box could have? (melectron = 9.11  10-31 kg, h = 6.626  10-34 J  s)
  A) 8.4  10-6 m B) 1.1  10-5 m C) 1.8  10-5 m D) 5.8  10-6 m E) 1.8  10-6 m

[shaquita]

Answer to Question 1

(a) 13,600 y (b) 743 decays/min

Answer to Question 2

E