1. Nuclear Radiation

2. Unstable isotopes emit radiation
Radiation: rays and particles emitted by unstable elements.
They decay based on their half-lives

3. Radiation can be natural or man-made

4. 2 types of Radiation: Electromagnetic Radiation : Pure energy
Consisting of interacting electrical & magnetic waves
Oscillating in space
Radio, microwave, infrared, visible light, Gamma, X-ray, UV with high energy

6. 2. Nuclear Radiation :
Atomic Nucleus
Proton + Neutron  Nuclear forces
Some isotope didn’t stable  they will randomly eject matter or energy to achieve greater stability  Radioactive.
Example: Uranium U-235 release neutrons and gamma ray photons.

7. Ionizing radiation: Nuclear Radiation
- An atom has lost or gained electron  ion
has enough energy to ionize matter
Can produce free radicals (molecules with unpaired electrons) which can cause cancer.
Geiger counter can detect it
Examples are alpha, beta, gamma, x-rays, UV light

8. non-ionizing radiation: Electromagnetic radiation (longwave length)
low energy
Just excite electrons
Examples are: Solar (visible light), radio broadcast, TV broadcast, microwave, and heat

9. 3 most common types of Radiation: Alpha Particle, Beta Particles, and Gamma Rays
Alpha Particle () : (same as helium atom)
Symbol:
Charge: +2 charge
Energy: low
Movement: SLOW
Penetration: little (blocked by paper)
Example: Alpha Decay: An alpha particle is released 5

10. An alpha particle
2 proton and 2 neutrons bound together and is emitted from the nucleus during some kinds of radioactive decay.

11. Beta Particle (β) : ionizing
Beta particles
Symbol: 0-1β or 0-1e
Charge: -1
Energy: medium
Movement: Fast
Penetration: Medium (blocked by metal foil)
Example: Beta Decay: electron is ejected from nucleus, neutron becomes proton

12. Beta Emission
An electron emitted from the nucleus during some kinds of radioactive decay.
10 n  11 p β
Nuclides above the band of stability are unstable because n/p is too large. To decrease the number of neutrons, a neutron can be converted into a proton and an electron. The electron is emitted from the nucleus as beta particle.

13. Gamma () rays: ionizing Symbol: 00 Charge: 0
Energy: very high
Movement: Very Fast (speed of light)
Penetration: FAR! (Only blocked by thick lead/concrete)
Example: Gamma Decay: High energy photons (electromagnetic radiation) are given off

14. Gamma Emission
High energy electromagnetic waves emitted from a nucleus as it changes from an excited state to a ground energy state.

15. Penetration of 3 types of radiation

16. Two additional types of Decay with Beta…
Positron Emission:
An antielectron is given off from the nucleus and a proton becomes a neutron
Symbol: 0+1e or 0+1β
Charge: +1

17. Positron Emission 11 p  10 n + 0+1β
A positron is a particle that has the same mass as an electron, but has a positive charge and is emitted from the nucleus during some kinds of radioactive decay.
11 p  10 n β
Nuclide below the band of stability are unstable because their n/p is too small. To decrease the number of protons, a proton can be converted into a neutron by emitting a positron.

18. Electron capture:
An inner orbital electron is pulled /captured by the nucleus and combines with a proton become a neutron
Symbol: 0-1e
Charge: -1

19. This electron capture :
n/p is too small
0-1 e p  10 n

20. Nuclear Reaction Nuclear Fission and Fusion
What do you think about when you hear these terms?

21. Nuclear Reactions
- Reactions involving changes in the nucleus of atoms
- These reactions release MUCH MORE energy then chemical reactions (which deal with electrons only)

22. Two major types of nuclear reactions:
Fission
Fusion

23. Nuclear Fission Nuclear fission = splitting of large, unstable atoms
Releases large amounts of energy
Uncontrolled, nuclear fission proceeds to completion with great speed.

24. Nuclear Fusion Nuclear Fusion:
Joining of smaller nuclei to form larger nuclei.
Releases far more energy than nuclear fission (3-4 xs more).
Unlike fission, fusion reactions can be easily controlled, by controlling the fuel flow.