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WEEK TWO
RADIOACTIVITY
- Radioactivity
- Nuclear reaction
- Nuclear power and atomic bomb
- Nigeria’s nuclear energy programme
Radioactivity
Radioactivity is the spontaneous decay or disintegration of the nucleus of the atom of an element during which it emits α, β or γ rays or a combination of any or all the three and energy ( or heat). Examples of radioactive elements are uranium, radium, radon, thorium, polonium, etc. These all have high atomic number (>82)
| Radiation | Alpha(α)particles | Beta(β) Particles | Gamma (γ)rays |
| Nature | Helium nuclei 42He | High Energy electrons | Electromagnetic wave of short wavelength |
| Velocity | 5 – 7% speed of light | Travel at approximate speed of light | Travel at speed of light |
| Nature of charge | Positively charged | Negatively charged | Neutral |
| Effects of magnetic field | Slightly deflected towards the negative plate | Strongly deflected towards the positive plate | No effects |
| Ionizing power | High | low | None |
| Penetrating power | Little penetrating power e.g. thin sheets of paper | Good penetrating power e.g. aluminum | High penetrating power e.g. leads |
| Mass | Massive particle | Small particle | No mass |
RADIOACTIVE DECAY
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