QUIZ

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Reminder!!!

• QUIZ 1 TODAY
• PLEASE SIT IN DARK COLORED CHAIRS

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Today1) Finish material from Wednesday2) Go
into todays material3) Quiz 1!
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Review - Isotopes

• 3) Isotopes are naturally abundant in different
  concentrations

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Review

• 1H hydrogen 99.985
• 2H deuterium 0.015
• 3H tritium trace amount

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Was there any D2 or T2 in these balloons?
H2

H2 O2
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Isotopes

• 4) Behave almost IDENTICALLY in chemical reactions

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Chemical Reactions

• 2 H2 O2 ? 2 H2O
• 2 D2 O2 ? 2 D2O
• 2 T2 O2 ? 2 T2O

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Chemical Reactions

• 2 H2 O2 ? 2 H2O
• 2 D2 O2 ? 2 D2O
• 2 T2 O2 ? 2 T2O

Is T2O radioactive?
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Isotopes

• 5) Isotopes behave differently in nuclear
  reactions.

What is a NUCLEAR reaction?
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Radioisotopes

• Isotopes which spontaneously undergo changes in
  the nucleus
• OR
• Isotopes that are radioactive.

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224 86
223 86
222 86
221 86

• Rn Rn Rn
  Rn
• Rn Rn Rn
  Rn
• Rn Rn Rn
  Rn
• Rn Rn Rn
  Rn
• Rn Rn Rn
  Rn

220 86
219 86
218 86
217 86
216 86
215 86
214 86
213 86
212 86
211 86
210 86
209 86
208 86
207 86
206 86
205 86
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Start
Radon nucleus
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(No Transcript)
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Finish
Radioactivity involves emissions from the nucleus.
Alpha particle
Polonium nucleus
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Lets Do It Again
86 protons 136 neutrons
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(No Transcript)
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Finish
2 protons 2 neutrons
84 protons 134 neutrons
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Alpha Decay of Radon

86 protons 136 neutrons
84 protons 134 neutrons
2 protons 2 neutrons
radon nucleus
polonium nucleus
alpha particle
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Alpha decay of radon

• Rn He Po

4 2
222 86
218 84
Alpha Particle
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The history and chemistry of radioactive particles
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Topics for Today

• Radiation
• History and discovery of radioactivity
• Alpha, beta, and gamma decay
• Quiz 1

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Readings

• Chapter 2 on the electromagnetic spectrum (page
  75)
• Chapter 7.7 - What is radioactivity?

How are gamma rays different than visible light?
How are they similar?
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Announcements

• Assignment 1 is due in our email boxes Monday
  before lecture!
• Please send to your TA and myself!

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PRELAB QUIZ for Week 2 Due before your lab next
week
Unlimited number of tries allowed this week only.
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Topics for Monday
Now you see it, now you dont
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Topics for Monday

• Alpha/Beta/gamma decay
• Radioactive decay series
• Half-life of radioisotopes
• Radioactive iodine

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Chapter 7

• Radioactive decay series, Figure 7.17
• (page 330)

Why are radium and thorium found in nature with
uranium?
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Chapter 11 Nutrition

• Minerals Macro and Micro
• (page 511)

How is iodine utilized in your body?
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Topics for Today

• Radiation
• History and discovery of radioactivity
• Alpha, beta, and gamma decay
• Quiz 1

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Alpha Decay of Radon
How did people first discover radiation?
ENERGY!!!

86 protons 136 neutrons
84 protons 134 neutrons
2 protons 2 neutrons
radon nucleus
polonium nucleus
alpha particle
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Back in Time

• 1893 and 1894 Marie Curie earns a Masters
  degree in Physics and Mathematics (age 19)

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Back in Time

• 1893 and 1894 Marie Curie earns a Masters
  degree in Physics and Mathematics (age 19)
• 1895 Roentgen discovers x-rays.

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Back in Time

• 1893 and 1894 Marie Curie earns a Masters
  degree in Physics and Mathematics (age 19)
• 1895 Roentgen discovers x-rays.

What are x-rays?
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• X-rays are short wavelength electromagnetic
  radiation.

Energy
Figure 2.6 (p. 75)
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Fig. 2.4 (p. 74)
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Figure 2.7 (p. 76)
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Back in Time

• 1893 and 1894 Marie Curie earns a Masters
  degree in Physics and Mathematics (age 19)
• 1895 Roentgen discovers x-rays.

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(No Transcript)
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Frau Anna Bertha Roentgens hand with wedding
ring Nov. 8, 1895
Modern day X-ray
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Dark areas in photograph? Light areas?
Frau Anna Bertha Roentgens hand with wedding
ring Nov. 8, 1895
Modern day X-ray
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What happened to the radiologists who held the
film plates?
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(No Transcript)
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Back in Time

• 1893 and 1894 Marie Curie earns a Masters
  degree in Physics and Mathematics (age 19)
• 1895 Roentgen discovers x-rays.
• 1900 Henri Becquerel discovers radiation

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Back in Time

• 1893 and 1894 Marie Curie earns a Masters
  degree in Physics and Mathematics (age 19)
• 1895 Roentgen discovers x-rays.
• 1900 Henri Becquerel discovers radiation
• 1903 The Curies (Marie and Pierre) discover
  polonium and radium in pitchblende.

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Pitchblende
How much radium can be found in TONS of
pitchblende?
Photo credit Jim Marshall, Walking tour of the
Elements
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Pitchblende
How much radium can be found in TONS of
pitchblende?
Just a couple of milligrams!
Photo credit Jim Marshall, Walking tour of the
Elements
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The Curies and Radium

• Saw radium as a potential for an anti-cancer
  agent (1,000,000 times more radioactive than
  uranium)
• Refused to patent this discovery for humanitarian
  reasons.

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Back in Time

• 1893 and 1894 Marie Curie earns a Masters
  degree in Physics and Mathematics (age 19)
• 1895 Roentgen discovers x-rays.
• 1900 Henri Becquerel discovers radiation
• 1903 The Curies (Marie and Pierre) discover
  polonium and radium.
• 1903 - The Curies and Becquerel win the Nobel
  Prize in physics

49
Back in Time

• 1893 and 1894 Marie Curie earns a Masters
  degree in Physics and Mathematics (age 19)
• 1895 Roentgen discovers x-rays.
• 1900 Henri Becquerel discovers radiation
• 1903 The Curies (Marie and Pierre) discover
  polonium and radium.
• 1903 - The Curies and Becquerel win the Nobel
  Prize in physics
• 1911 Marie Curie wins second Nobel Prize

50
Back in Time

• 1903 The Curies (Marie and Pierre) discover
  polonium and radium.
• 1903 - The Curies and Becquerel win the Nobel
  Prize in physics
• 1911 Marie Curie wins second Nobel Prize
• 1934 Marie Curies dies from leukemia

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Early Researchers
About 40 of the early radioactivity researchers
died of cancer.
At the time, why was this surprising?
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What makes these radioisotopes so dangerous?
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• They emit high energy particles and / or
  electromagnetic radiation
• These emissions hit other atoms and molecules and
  ionize them.
• The radioactive substance will change its
  identity.

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• They emit high energy particles and / or
  electromagnetic radiation
• These emissions hit other atoms and molecules and
  ionize them.
• The radioactive substance will change its
  identity.

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Review - Alpha Decay of Radon
ENERGY!!!

86 protons 136 neutrons
84 protons 134 neutrons
2 protons 2 neutrons
radon nucleus
polonium nucleus
alpha particle
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• They emit high energy particles and / or
  electromagnetic radiation
• These emissions hit other atoms and molecules and
  ionize them.
• The radioactive substance will change its
  identity.

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What is the most abundant compound in the human
body?
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Ionizing radiation (alpha, beta, or gamma)
H2O
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electron


H2O
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Ionizing radiation
e-


H2O
H2O
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In other words,

• H2O H2O e

Ionizing radiation
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• They emit high energy particles and / or
  electromagnetic radiation
• These emissions hit other atoms and molecules and
  ionize them.
• The radioactive substance will change its
  identity.

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• Uranium (eventually) decays to radon. . .

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• Uranium (eventually) decays to radon. . .

So what ?
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• Uranium solid. Stuck in a rock and weakly
  radioactive.
• Radon gas. Free to penetrate into the human
  lungs.

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Quiz 1

• Please hand the quiz to your TA when you are
  finished.
• Have a great weekend!