1. Nuclear Chemistry
Chapter 21

2. Radioisotopes Nuclei of unstable isotopes are called radioisotopes.
An unstable nucleus releases energy and/or mass by emitting radiation during the process of radioactive decay

3. Radiation Three Types Alpha  Helium Nucleus Beta  Electron
Gamma  Light wave

4. Symbols
Alpha
Beta
Gamma

5. Radiation

6. Radiation

7. Nuclear Symbols
Table O

8. Nuclear Stability
For smaller atoms, a ratio of 1:1 neutrons to protons helps to maintain stability
C-12, N-14, O-16
For larger atoms, more neutrons than protons are required to maintain stability
Pb-207, Au-198, Ta-181

9. Nuclear Stability

10. Radioactive Decay
Radioisotopes will undergo decay reactions to become more stable
Alpha Decay
Beta Decay
Positron Emission
Electron Capture

11. Alpha Decay

12. Beta Decay

13. Positron Emission

14. Electron Capture
37 81 𝑅𝑏 + −1 0 𝑒 → 𝐾𝑟

15. Transmutations
Any reaction where one element is transformed into a different element
Two main types
Natural
Artificial

16. Example X

17. Example X

18. Example X

19. Fission Splitting of a larger atom into two or more smaller pieces
Nuclear Power Plants
One Example:

20. Fission

21. Fusion Joining of two or more smaller pieces to make a larger piece
Sun, Stars
One Example:

22. Fusion

23. Energy Production
Energy is produced by a small amount of mass being converted to energy
More energy is produced by fusion than any other source
E=mc2

24. Mass Difference
The mass of a nucleus weighs less than the mass of the individual protons and neutrons
He Nucleus  u
2 protons 2( )
2 neutrons 2( ) u

25. Mass Defect Mass difference between nucleus and individual particles
Nucleons u
Nucleus u
Mass Defect u

26. Nuclear Binding Energy
In order to break apart the individual particles in a nucleus, energy must be added.
The added energy is converted back to mass
When particles form a nucleus, energy is released

27. Nuclear Binding Energy per Nucleon

29. Half Life
Amount of time for half the atoms in a radioactive sample to decay into a new element
Measure of time, t1/2

30. Half Life Equation
𝑙𝑛 𝑁𝑡 𝑁𝑜 =−𝑘𝑡
𝑙𝑛 𝑁𝑜 𝑁𝑡 =𝑘𝑡

31. Half Life Equation
𝑙𝑛 𝑁𝑜 𝑁𝑡 =𝑘𝑡
𝑙𝑛 2 1 =𝑘 𝑡 1/2
𝑘= 𝑡 1/2

32. Example