1. Unstable Nuclei & Radioactive Decay

2. Chemical reactions involve changes in the electrons surrounding an atom.
Nuclear reactions involve changes in the nucleus of an atom.

3. Radioactive atoms emit radiation because their nuclei are unstable.
Unstable nuclei lose energy by emitting radiation in a spontaneous process called radioactive decay.

4. Review of Terms
Isotopes - atoms of the same element with different mass numbers (different numbers of neutrons)
Radioisotopes - isotopes of an element that radioactively decay (are unstable)
Radioactive decay – the process through which an unstable nucleus changes into another more stable nucleus by giving off a particle and some radiation
Radiation – energy that can be transmitted through a vacuum in the form of a wave
Examples: light, X-Rays, UV Rays, IR Rays, Gamma Rays, Radio Waves

5. What elements are radioactive?
Occur in Nature
84 – 92 (Polonium – Uranium)
Made in a Laboratory
43(Tc), 61(Pm), 93 – 116 (as of now)

6. Nuclear Equation
Shows the atomic numbers and mass numbers of the particles involved.

7. Alpha α Contains 2 protons & 2 neutrons.
Alpha Particle has a - Mass of 4 and a Charge of +2
Fairly large particle; doesn’t penetrate well (paper can stop it)

8. What is an alpha radiation?

9. Beta β Each beta particle is an electron with -1 charge.
Therefore a beta particle has a charge of -1
Small particle; moves at close to the speed of light; requires 1-2 in. of metal to stop

10. What is beta radiation?

11. Gamma γ High energy radiation that posses no mass
Because they are neutral, gamma rays are not deflected by electric or magnetic fields.

12. Video: Radiation and Radioactive Decay

13. Half - Life
The amount of time it takes for one-half of a given mass or number of atoms to decay

14. Video: Carbon Dating

15. Applications of Nuclear Chemistry
How was Radiation Discovered?
Wilhelm Roentgen (1895) - discovered X-Rays
Henri Becquerel (1896) - found that Uranium emits radiation onto photographic film - X-Rays
Marie and Pierre Curie (early 1900’s) - found Radium (another radioactive element) and Polonium
Found it ionized air particles and made phosphorescent objects glow
Found that when radiation is emitted, other elements are then created
Also found radiation causes severe health effects (They both died of cancer)
Ernst Rutherford (1912) – gold foil experiment; discovered the nucleus

16. Nuclear Bombardment Reactions
Ernest Rutherford first did this in 1919
Particle Accelerator - Basic Idea: Particle accelerators use a series of magnets to create a path that the nuclei must follow (nuclei are positively-charged, so they interact with magnets).
When a collision is desired, the orientation of the magnets is changed to change the path of the nuclei; two types:
Linear Accelerator – straight path, particles can get to about 90% speed of light
Tevatron – “big donut”; only a few in the USA – 99% speed of light

17. Video: Nuclear Reactions

18. CERN: Super Collider

19. Nuclear Reactors
How Do Nuclear Power Plants Work?
What went wrong at Chernobyl?

20. Current Events Submit via socrative… Room #335755
What happened in Fukushima Japan?
Find 2 nuclear power plants near MI
When were they built?
What could happen to you if a disaster were to occur?