Lesson 1 What is radon?

Slide 1-1 Which characteristics apply to radon? Liquid Gas Solid Colorless Grayish-green Greenish-blue Smells like ozone Has no smell Has no taste Tastes metallic Tastes like chicken Occurs in nature Made by humans Reacts readily chemically Does not readily react chemically (is inert) Has a static electrical charge Has no static electrical charge Radioactive Not radioactive Harmful to human health Harmless to human health See handout 1-1

Slide 1-2 Characteristics of radon Liquid Gas Solid Colorless Grayish-green Greenish-blue Smells like ozone Has no smell Has no taste Tastes metallic Tastes like chicken Occurs in nature Made by humans Reacts readily chemically Does not readily react chemically (is inert) Has a static electrical charge Has no static electrical charge Radioactive Not radioactive Harmful to human health Harmless to human health

Slide 1-3 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

Slide 1-4 Background for understanding radioactivity Simple atom Nucleus –Protons (+ or positive charge) –Neutrons (no charge) Electrons (- or negative charge)

Slide 1-5 Radon (Rn) atom Radon is an element: a basic unit of matter Atomic number =Number of protons 86 Atomic mass or mass number = Number of protons + number of neutrons Varies

Slide 1-6 Naturally occurring radon isotopes Isotopes: different forms of an element with different atomic masses Number of protons Number of neutrons Atomic mass Radon Radon Radon

Slide 1-7 Radiation = energy emitted as invisible Particles Waves Rays Isotopes May be stable or unstable Unstable isotopes (radioactive) decay spontaneously (change to another element) called –Decay products –Progeny –Daughters During decay, unstable isotopes give off radiation

Slide 1-8 Radon decay series Radon-222 Polonium-218 Bismuth-214 Polonium-214 Lead-210 Lead-214

Slide 1-9 Radon and its decay products RadonDecay products GasSolid Chemically inactiveChemically active No static electrical charge Electrically charged Primary source of cell damage leading to lung cancer

Slide 1-10 Types of radiation released Alpha ()Beta ()Gamma () Relatively large mass Relatively small mass No mass = 2 protons and 2 neutrons = 1 electron= pure energy (electromagnetic radiation) Electrical charge of +2 Electrical charge of -1 No electrical charge Moves slowlyMoves quicklyMoves at the speed of light Least penetratingModerately penetrating Most penetrating Most damaging to human health

Slide 1-11 Radiation released in radon decay Radon-222 +  Polonium-218 +  Bismuth-214 +  Polonium-214 +  Lead-210 Lead-214 +   particles damage lung cells

Slide 1-12 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

Slide 1-13 Hypothetical example 1-day half-life in box of atoms

Slide 1-14 Half-life of radon 3.8 days In 3.8 days Radon can move from soil, rock, and water into air in a home –People breathe in the radon As radon decays –It releases radiation –It creates radon decay products, which may remain in lungs and release more radiation as they decay Note: Radon gas is continually entering a home and decaying

Slide 1-15 Half-lives of radon and its decay products Radon days Polonium minutes Bismuth minutes Polonium microseconds Lead years Lead minutes Short half- lives

Slide 1-16 Summary No color No smell No taste No electrical charge Gas Radioactive –Releases damaging  particles during decay process Naturally occurring Does not readily react chemically Harmful to human health Radon is an element. What are its characteristics? See handout 1-2

Slide 1-17 Questions?

Slide 1-18 Check your understanding See handout 1-3