Question 1
How many
14C atoms are in a charcoal sample that has a decay rate of 3,500 disintegrations per min? (For
14C, t
1/2 = 5,730 yr.)
◦ 2.9 × 10
7 atoms
◦ 8.0 × 10
–7 atoms
◦ 1.4 × 10
14 atoms
◦ 1.5 × 10
13 atoms
◦ 6.02 × 10
20 atoms
Question 2
How old is a bottle of wine if the tritium (
3H) content is 25% that of a new wine? The half-life of tritium is 12.5 years.
◦ 0.25 yr
◦ 3.1 yr
◦ 25 yr
◦ 38 yr
◦ 50. yr