Name: ______TP: ______
/ 1. What does “A” represent in this notation? / 2. What does “Z” represent in this notation?3. Represent a proton in the notation shown above (use “p” as the symbol for a proton): / 4. Represent a neutron in the notation shown above (use “n” as the symbol for a neutron): / 5. Represent an electron in the notation above (use “e” as the symbol for an electron):
Elements that emit tiny, invisible particles from their nuclei are described as radioactive. Radioactive atoms emit small particles to gain stability that is lost when an element becomes an isotope. There are many different types of radioactive emissions: alpha (α) rays, beta (β) rays, and gamma (γ) rays.
6. Alpha radiation occurs when an unstable nucleus emits a small piece of itself. An alpha particle consists of 2 protons and 2 neutrons. Represent an alpha particle in the notation shown above. Use the symbol “α.” / 7. What element has the same notation as an alpha particle?
8. True or False: After an element has emitted an alpha particle, it has the same mass it started with. If this statement is false, correct it to make it true.
9. True or False: When an element emits an alpha particle, it is still the same element. If this statement is false, correct it to make it true.
/ 10. The picture to the left shows a reaction. Is this reaction balanced? Why or why not?
11. Nuclear reactions must also be balanced. Imagine that you start with uranium-238, which is very radioactive. Show uranium-238 undergoing alpha decay:
12. The reaction on the previous page can be separated into two sides (separated by the arrow). Are the two sides of your nuclear reaction balanced? Prove it below in a manner similar to the picture shown next to #10.
13. Write a nuclear equation for the alpha decay of Ra-224. Check your answer (and show your work) to prove that the equation is balanced.
14. Write the nuclear equation for the alpha decay of Po-216. Check your answer (and show your work) to prove that the equation is balanced.
15. Beta radiation occurs when an unstable nucleus emits an electron. This electron is created when a neutron is converted into a proton. Show this reaction in words below: / 16. Use the explanation of beta radiation in #15 to write out the correct notation for a beta particle. Use the symbol “β.”
17. Write the nuclear equation for the beta decay of radium-228. Check your answer (and show your work) to prove that the equation is balanced.
18. Write the nuclear equation for the beta decay of Bk-249. Check your answer (and show your work) to prove that the equation is balanced.
19. Write the nuclear equation for the beta decay of Ac-228. Check your answer (and show your work) to prove that the equation is balanced.
20. What do you notice happens to the atomic number of the element when it emits a beta particle? / 21. Gamma radiation is different from alpha and beta radiation in that a gamma particle has no charge and no mass. Instead, gamma radiation releases large amounts of energy. True or False: When a gamma ray is emitted from a radioactive atom, it will change the atomic number, but not the mass number. If this statement is false, correct is so that it is true.
22. Use the symbol “γ” to represent a gamma particle in proper notation below. / 23. Write the nuclear reaction for the emission of a gamma ray from uranium-238. Check your answer (and show your work) to prove that the equation is balanced.
24. Alpha particles can be stopped by a sheet of paper, by clothing, or even by air. Beta particles can be stopped by a piece of metal or a thick piece of wood. Gamma rays can be stopped by several inches of lead or thick slabs of concrete. Below, use the symbol “<” to represent the penetrating power of alpha, beta, and gamma particles from least to greatest.
25. Look at all of the nuclear equations you’ve written out. Do any of them result in a stable element? If not, what do you think an element has to do eventually gain stability?
26. PUSH IT TO THE LIMIT: Write a partial decay series for Rn-220 undergoing the sequential decays: α, α, β, α.
PUSH IT TO THE LIMIT.