Lesson 1
Which characteristics apply to radon? Liquid Gas Solid Colorless Grayish-green Greenish-blue Has no smell Has no taste Tastes metallic
Liquid Gas Solid Colorless Grayish-green Greenish-blue Smells like ozone Has no smell Has no taste Tastes metallic Tastes like chicken
Is there radon in this room? Why would we care? - Radon is harmful to human health
- Leading cause of lung cancer among nonsmokers
How would we know if there were radon in the room? - Radon may occur anywhere
- Radon has no color, odor, or taste, so we cannot detect with our senses
- We can tell only by measuring
Background for understanding radioactivity Simple atom Nucleus - Protons (+ or positive charge)
- Neutrons (no charge)
Electrons (- or negative charge)
Radon (Rn) atom
Naturally occurring radon isotopes
Isotopes Unstable isotopes (radioactive) decay spontaneously (change to another element) called - Decay products
- Progeny
- Daughters
During decay, unstable isotopes give off radiation
Radon decay series
Radon and its decay products
Radiation released in radon decay
Rate of radioactive decay Expressed as half-life - Amount of time required for half of atoms to decay
Hypothetical example: a box of atoms of an element with half-life of 1 day - After 1 day, 50% of atoms will have decayed
- After 2 days, 50% of remaining atoms will have decayed
- Box would contain 25% of original number of atoms
- And so on
Hypothetical example 1-day half-life in box of atoms
Half-life of radon 3.8 days In 3.8 days - People breathe in the radon
As radon decays Note: Radon gas is continually entering a home and decaying
Half-lives of radon and its decay products
Summary No color No smell No taste No electrical charge
Questions?
Check your understanding
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