Question

The energy level diagram for a hydrogen atom is shown. The following questions are about the energy

levels of the hydrogen atom. An electron jumps from the n = 5 level to the n = 1 level.

1. Will this result in an emission line, or an absorption line in the

spectrum of this atom? 1. _________________

2. Which excited state did the electron start at?

2. _________________

3. What is the principal quantum number of the electron when it is

at the level n = 1? 3. _________________

4. Which series does this jump belong to?

4. _________________

5. What is the energy, in Joules, of the energy packet or particle associated with this jump?

5. _________________

6. What is the frequency of this energy packet? 6. _________________

7. What is the wavelength, in nanometers (nm) of the photon associated with this jump?

7. _________________

8. A photon having an energy of 10.2 eV now strikes this hydrogen atom. Can the photon be absorbed

by the atom? If so, describe the electron jump that will occur. If not, explain why not.

8. _________________

9. What is the frequency of this photon? 9. _________________

10. What is the wavelength in nanometers (nm) of this photon? 10. ________________

The following questions are about nuclear isotopes.

11. Explain what isotopes are. How are the isotopes of a particular element similar? How are they

different?

___________________________________________________________________________

12. An element has a mass number of 38 and is the 15th element on the periodic table. How many

neutrons does it have? 12. ________________

The following question is about the fundamental forces.

13. List the four force interactions in the universe (in order from strongest to weakest) together with

their associated particles.

___________________________________________________________________________

The decay curve of a radioactive nuclide

sample is shown. Its initial activity is

measured to be X Bq.

14. What is the population at t = 8.0

hours? 14. ________________

15. After how many half lives will the

population be 125 nuclides?

15. ________________

16. What will be the level of activity (in

terms of X) after two half lives have

elapsed?

16. ________________

17. What would the activity of the above sample be if we tripled its size? 17. ________________

18. If the initial activity of 0.365 grams of the above sample is Y Bq, what would the activity be if we

increased the initial sample to 0.950 grams? 18. ________________

A radioactive nuclide X having a mass of 65.0 grams is sealed in a container having a mass of 5.00

grams. The nuclide X decays into the nuclide Y. The nuclide X has a half life of 6.00 hours.

19. What will the mass of nuclide X be after 24 hours have elapsed? 19. ________________

20. What will the mass of nuclide Y be after 24 hours have elapsed? 20. ________________

21. What will the mass of the sealed container be after 24 hours have elapsed? 21. ________________

These questions are about radioactive half-life.

22. 256 grams of a radioactive sample decays to 4 grams in 120 minutes. What is the half life of the

sample? 22. ________________

23. Suppose the activity of a radioactive sample decreases from X Bq to X/16 Bq in 80 minutes. What is

the half-life of the substance? 23. ________________

Answer 1