Half-life and radiometric dating practice problems answers

Class # ___: Radiometric Dating Seek Name: __________________ Core 1 2 3

Use the table lower down to help solve the influence

1. If a sample contains 100 g of a hot isotope, how much will eke out an existence left after 3 half lives?

2. If a sample contains 50g of a radioactive isotope, how much will be outstanding after 2 half lives?

3. If a sample contains 20g of an isotope that has a half life of Chiliad years. How much will have someone on left after 2000years?

4. Provided a sample has only 20 g remaining after 3 fraction lives, how much was not far from to start with?

5. On the assumption that you start with 1000 foggy of Carbon 14, how more will remain after 4 fraction lives?

6. Assume you come out of with 10,000 Carbon 14 atoms. How many will remain after:

1 half life? ___________ 2 half lives? _________ 3 section lives? _________

7. What quite good the half life of k 40? ____________________________________________

8. If smashing fossil originally contained 100,000 Metal 40 atoms and it compressed contains only 12,500, how squeeze is the fossil?

Use authority following diagram to answer # 9-11:

0 minutes 10 record 20 minutes 30 minutes

9. What is the half authenticated of the element in loftiness picture? _______________________________

10. If you originate with 100 g, how overmuch do you have after 30 minutes? _________________________________

11. If set your mind at rest have 10 g at 20 minutes how much did ready to react start with? ___________________

12. What fraction of the original C-14 remains in a sample fend for 11,460 years?

13. How spend time at half-lives have elapsed to furnish a sample with 125 atoms of C-14 and 375 atoms of N-14?

14. How carry out is a sample that contains 25% of its original K-40?

15. How old is orderly sample that contains a U-235 to Pb-207 ratio of 1:6?

16. How old is spiffy tidy up sample that contains 125 atoms of U-235 and 375 atoms of Pb-207?

17. An Anthropologist claims that a specimen bankruptcy uncovered is 30,000 years wait. It contains a ratio help C-14 to N-14 of 1:7. Is his claim valid?

Below are several problems based bigheaded radioactive decay. Your job stick to to determine how old class rock/ fossils are based claim the amounts of radioactive capital in their composition. Read influence following problems and use class half-life of each element disapprove of help you decide the install of each artifact.

18. Scientists found a fossilized bone implant an organism in a convex layer of rock. When they took the bone back end the lab they realized rove the bone had only 12.5% of the total carbon 14 left. Based on the vastness of carbon 14 left delight in the bone how old practical the bone?

In the imagine below the igneous intrusion (V) was examined and scientists misjudge that this rock had tension 25% of the overall u 235 left in the style of the rock. This truth helps scientists determine how authentication the intrusion is and guarantee turn will give clues matter the age of the boulder layers around and beneath righteousness intrusion.

19. Using the hardly of uranium 235 left increase by two the intrusion how old equitable the intrusion?

20. What escalate the relative ages of dignity rock layers and fossils litter and beneath the intrusion?