1/ The radioactive count rate in living organisms due to the presence and decay of C-14 is 16 min-1 per gram of carbon. A wood carving was dug up and found to have a count rate of 4 min-1 per gram of carbon. How old is the wood? The half-life, t1/2, of C-14 is 5,600 years.
2/ Given 1.000 g of Sr-90 today. After 2.0 years, it remains 0.953 g.
(a) What is the half-life of Sr-90?
(b) How much strontium will remain after 5.00 years?
3/ What effect, if any, does the inclusion of an extra neutron in the nucleus of nitrogen on its chemical properties? Give a reason for your answer.