1. Nuclear Chemistry

2. The study of reactions that take place in the nucleii of atoms

3. Chemical Reactions In normal chemical reactions, only the electrons are involved

4. Radioactive Nucleii A nucleus that spontaneously decomposes

5. Isotopes Elements with the same atomic number, but different mass number

6. Isotopes Elements with = numbers of protons, but  numbers of neutrons

7. Isotopes All elements have at least one radioactive isotope

8. Radiation The emission of particles & rays from spontaneously decomposing nucleii

9. Modes of Decay Alpha emission Beta emission Gamma emission Positron emission K-electron capture

10. Alpha Particle (  ) Helium nucleus 2 protons & 2 neutrons mass = 4 amu charge = +2 Penetration power: small

11. Beta Particle (  ) High speed electron 1 electron mass = 1/1836 amu charge = -1 Penetration power: medium

12. Gamma Ray (  ) High energy photon Electromagnetic wave mass = 0 charge = 0 Penetration power: great

13. Positron (  ) Positive electron 1 positive electron mass = 1/1836 amu charge = +1 Penetration power: medium

14. K-capture The capture of an inner level e - by the nucleus 1 electron mass = 1/1836 amu charge = -1

15. Nuclear Symbol Alpha: 2 4 He or 2 4  Beta: -1 0 e or –1 0  Gamma: 0 0  Positron: +1 0 e K-electron: -1 0 e

16. Fission The splitting of a nucleus into smaller nucleii involving the release of energy

17. Fusion The combining of smaller nuclei into a larger one involving the release of energy

18. Transmutation Rxns Nuclear reactions in which one element is changed into another

19. Transmutation Rxns Reactions in which the nucleus of an atom is changed

20. Transmutation Rxns Both fission & fusion are examples of transmutation rxns

21. Transmutation Rxns Can occur through emission of or bombardment by radioactive particles

22. Transmutation Rxns  emission of Pm-142  emission of U-238 K-capture by O-15  addition of O-18

23. Transmutation Rxns  emission of  U   followed by two separate  emissions:

24. Transmutation Rxns  bombardment of Th  followed by two separate  emission:

25. Predict Products a Neutron absorption by U   followed by two separate  emission:

26. Predict Products  emission of O-18 followed by a  emission:

27. Predict Products K-capture by V-45 followed by neutron emission then  emission

28. Decay Rate The rate at which a radioactive nucleus breaks down

29. Half-Life The time it takes for 50 % of the radioactive nucleii to decompose

30. Decay Rate Rate = kdX/dt ln(X o /X) = kt 1/2 k = 0.693/t 1/2 t 1/2 = half-life

31. 1st Order Age Dating Formula t = ln(X i /X f )t 1/2 0.693

32. Calculate the age of a skeleton found with 0.125 % C-14 when atmospheric C-14 = 1.00 %. t 1/2 C-14 = 5720 yr

33. Calculate the age of a tooth found with 0.00132 % C-14 when atmospheric C-14 = 1.00 %. t 1/2 C-14 = 5720

34. Calculate the age of a bone found with 0.000300 % C-14 when atmospheric C- 14 = 1.00 %. t 1/2 C-14 = 5720

35. Mass-Energy Relations  E =  mc 2

36. Nuclear Fact The mass of any nuclei is different than the sum of the masses of its protons & neutrons

37. Nuclear Fact The energy corresponding to the mass difference can be solved using:  E =  mc 2

38. Binding Energy The energy that holds a nucleus together which corresponds to  m of nucleus

39. In an atomic bomb, 40.00 kg of U-235 (235.401) is split into Ba-144 (14 3.223) + Kr-89 (89.335) + 2 neutrons (1.014). A) Calculate the energy released. B) Calculate the wavelength of the  ray

40. Show neutron bombardment of Ra-223 followed by 3 alpha emissions