1. Nuclear Chemistry

2. Radioactivity:
Definition: occurs when the nucleus of an unstable atom emits ionizing radiation
Radiation- the movement of energy by particles or waves
Electromagnetic radiation

3. Non-ionizing Radiation- low energy; usually not harmful
Ionizing Radiation- carry enough energy to “ionize” atoms
Elements after atomic number 83 are radioactive

4. Isotope –
Radioisotope-

5. Nuclear Reactions
Involve a change in the atom’s nucleus (protons and neutrons)
Types:
Fission
Fusion

6. Types of Radiation Alpha α (Alpha Decay) Alpha particle = 2p+ and 2n0
U  Th He ϒ
Alpha particle is a He nucleus
ϒ accounts for energy lost during reaction
In the reaction, we must conserve p+ and n0
Don’t penetrate too far, but can cause skin problems
Sources have a long half-life (around for a long time)
Discovered by Rutherford and his students (Geiger)

7. Types of Radiation Beta ϐ (Beta Decay)
Beta particle: fast moving electron (-1 charge)
ϐ or e
Formed when a neutron is split into a proton and a ϐ particle (electron)
n  p ϐ ϒ
There is no change in the mass #, only in atomic #
Atomic # changes because the e- emitted during ϐ rxn (ϐ decay) has been removed from a neutron (charge of 0) leaving behind a proton
Rb  Sr e-
Damaging to skin because they can travel through a few inches of tissue

8. Types of Radiation Gamma Rays
Gamma Rays: high energy radiation (electromagnetic) that is massless
No electrical charge
Often accompany α and ϐ reactions
Harmful- can deeply penetrate skin

10. Electromagnetic Spectrum

11. Practice Equations:

12. Radiation Exposure Accumulated Doses
Measured in units called rem: measures doses of radiation while accounting for energy of radiation, type of living tissue absorbing radiation and time of exposure.
Background radiation- Where does this it come from?

13. Radiation Exposure How do we detect radiation? Geiger Counter
Tube filled with gas that absorbs radiation and becomes ionized  charge  current  measure the amount of radiation