Adapted by Nelson Nuñez-Rodriguez
Conditions of Use:
Unless otherwise noted, this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Chapters derived from:
By David W. Ball
Attribution-NonCommercial-ShareAlike
CC BY-NC-SA
Click on the printer icon at the bottom of the screen
Make sure that your printout includes all content from the page. If it doesn't, try opening this guide in a different browser and printing from there (sometimes Internet Explorer works better, sometimes Chrome, sometimes Firefox, etc.).
If the above process produces printouts with errors or overlapping text or images, try this method:
Click here to return to Chapter 7
QUESTION | ANSWER |
1. Do all isotopes have a half-life? Explain your answer. |
1. Only radioactive isotopes have a half-life. |
3. How long does it take for 1.00 g of palladium-103 to decay to 0.125 g if its half-life is 17.0 d? |
3. 51.0 d |
5. It took 75 y for 10.0 g of a radioactive isotope to decay to 1.25 g. What is the half-life of this isotope? |
5. 25 y |
7. The half-live of americium-241 is 432 y. If 0.0002 g of americium-241 is present in a smoke detector at the date of manufacture, what mass of americium-241 is present after 100.0 y? After 1,000.0 y? |
7. 0.000170 g; 0.0000402 g |
9. Explain why the amount left after 1,000.0 y in Exercise 7 is not one-tenth of the amount present after 100.0 y, despite the fact that the amount of time elapsed is 10 times as long. |
9. Radioactive decay is an exponential process, not a linear process. |
11. An artifact containing carbon-14 contains 8.4 × 10−9 g of carbon-14 in it. If the age of the artifact is 10,670 y, how much carbon-14 did it have originally? The half-life of carbon-14 is 5,730 y. |
11. 3.1 × 10−8 g |
Library Info and Research Help | reflibrarian@hostos.cuny.edu (718) 518-4215
Loans or Fines | circ@hostos.cuny.edu (718) 518-4222
475 Grand Concourse (A Building), Room 308, Bronx, NY 10451