Podcast
Questions and Answers
What percentage of electricity in the US is provided by nuclear reactors?
What percentage of electricity in the US is provided by nuclear reactors?
- 50%
- 10%
- 20% (correct)
- 30%
Who first discovered radioactivity?
Who first discovered radioactivity?
- Marie Curie
- Ernest Rutherford
- Paul Villard
- Antoine Henri Becquerel (correct)
What is a requirement for a nucleus to be considered radioactive?
What is a requirement for a nucleus to be considered radioactive?
- It has 84 or more protons. (correct)
- It must have equal numbers of neutrons and protons.
- It has a stable neutron to proton ratio.
- It contains fewer than 84 protons.
What type of radiation results from the discharge of alpha particles?
What type of radiation results from the discharge of alpha particles?
Which statement about beta radiation is true?
Which statement about beta radiation is true?
What did Paul Villard discover?
What did Paul Villard discover?
Which of the following nuclei is radioactive?
Which of the following nuclei is radioactive?
What happens to the element during alpha decay?
What happens to the element during alpha decay?
What does the notation –1β indicate in the context of beta decay?
What does the notation –1β indicate in the context of beta decay?
Which type of ionising radiation is able to penetrate most substances and requires dense materials like lead for shielding?
Which type of ionising radiation is able to penetrate most substances and requires dense materials like lead for shielding?
What is the primary danger of Radon-222 accumulating in the lungs?
What is the primary danger of Radon-222 accumulating in the lungs?
What is the unit 'rem' used to measure?
What is the unit 'rem' used to measure?
What happens when ionising radiation strikes living tissues?
What happens when ionising radiation strikes living tissues?
What are typical effects of acute exposure to radiation (greater than 50 rem)?
What are typical effects of acute exposure to radiation (greater than 50 rem)?
What form of radiation is denoted by the symbols 00𝛾 or simply 𝛾?
What form of radiation is denoted by the symbols 00𝛾 or simply 𝛾?
Which type of radiation has the lowest penetrating power and can be stopped by paper?
Which type of radiation has the lowest penetrating power and can be stopped by paper?
What type of radiation is emitted from the decay of Potassium-40, which is common in foods?
What type of radiation is emitted from the decay of Potassium-40, which is common in foods?
What can happen to enzymes and cellular structure following acute radiation exposure?
What can happen to enzymes and cellular structure following acute radiation exposure?
What is half-life in radioactive isotopes?
What is half-life in radioactive isotopes?
Which isotope is commonly used for radiocarbon dating?
Which isotope is commonly used for radiocarbon dating?
What is the half-life of Technetium-99m?
What is the half-life of Technetium-99m?
In Positron Emission Tomography (PET), what does Carbon-11 emit during decay?
In Positron Emission Tomography (PET), what does Carbon-11 emit during decay?
Why are cancer cells more susceptible to gamma rays?
Why are cancer cells more susceptible to gamma rays?
What is nuclear fission?
What is nuclear fission?
What method increases the abundance of a desired isotope like U-235?
What method increases the abundance of a desired isotope like U-235?
How is nuclear waste typically managed for long-term safety?
How is nuclear waste typically managed for long-term safety?
What is the effect of nuclear power on carbon emissions?
What is the effect of nuclear power on carbon emissions?
What does the term 'radiotracers' refer to?
What does the term 'radiotracers' refer to?
Which isotope is primarily used in Gamma Knife radiosurgery?
Which isotope is primarily used in Gamma Knife radiosurgery?
What is the primary goal of adding a neutron to U-235 in isotope enrichment?
What is the primary goal of adding a neutron to U-235 in isotope enrichment?
What happens during positron/electron annihilation?
What happens during positron/electron annihilation?
Why is the process of nuclear fission significant in energy generation?
Why is the process of nuclear fission significant in energy generation?
What is a characteristic feature of beta radiation?
What is a characteristic feature of beta radiation?
Which of the following statements about radioactive nuclei is true?
Which of the following statements about radioactive nuclei is true?
What happens to the atomic number of an element during beta decay?
What happens to the atomic number of an element during beta decay?
What is emitted during the alpha decay of an atomic nucleus?
What is emitted during the alpha decay of an atomic nucleus?
Which element's isotope is commonly known for its use in radiocarbon dating?
Which element's isotope is commonly known for its use in radiocarbon dating?
What is the main purpose of nuclear reactors in the US?
What is the main purpose of nuclear reactors in the US?
Which particle is associated with alpha radiation?
Which particle is associated with alpha radiation?
What is one condition that must be met for a nucleus to be considered radioactive?
What is one condition that must be met for a nucleus to be considered radioactive?
What does gamma radiation primarily consist of?
What does gamma radiation primarily consist of?
Which statement accurately describes the penetrating power of alpha particles?
Which statement accurately describes the penetrating power of alpha particles?
What biological damage can result from exposure to Radon-222?
What biological damage can result from exposure to Radon-222?
What is the primary danger of gamma rays when they interact with biological tissues?
What is the primary danger of gamma rays when they interact with biological tissues?
What unit is commonly used to express the dose of ionizing radiation received by humans?
What unit is commonly used to express the dose of ionizing radiation received by humans?
How does acute exposure to radiation greater than 50 rem typically affect the body?
How does acute exposure to radiation greater than 50 rem typically affect the body?
Which type of radiation has the highest penetrating power?
Which type of radiation has the highest penetrating power?
What is a common consequence of ionizing radiation striking living tissues?
What is a common consequence of ionizing radiation striking living tissues?
What type of radioactive decay does Radon-222 undergo?
What type of radioactive decay does Radon-222 undergo?
What is a primary source of background radiation for residents in the US?
What is a primary source of background radiation for residents in the US?
What is the half-life of Carbon-14?
What is the half-life of Carbon-14?
How does Gamma Knife radiosurgery primarily affect cancer cells?
How does Gamma Knife radiosurgery primarily affect cancer cells?
What is the main purpose of isotope enrichment?
What is the main purpose of isotope enrichment?
What type of decay does Technetium-99m undergo?
What type of decay does Technetium-99m undergo?
What characterizes a fission chain reaction?
What characterizes a fission chain reaction?
Which isotope is frequently used in Positron Emission Tomography (PET)?
Which isotope is frequently used in Positron Emission Tomography (PET)?
What defines half-life in the context of radioactive isotopes?
What defines half-life in the context of radioactive isotopes?
What is a significant advantage of nuclear power compared to coal-fired power?
What is a significant advantage of nuclear power compared to coal-fired power?
During positron/electron annihilation, what is produced?
During positron/electron annihilation, what is produced?
What is a primary method for managing nuclear waste?
What is a primary method for managing nuclear waste?
Which of the following best describes nuclear fission?
Which of the following best describes nuclear fission?
What is the role of positrons in PET scans?
What is the role of positrons in PET scans?
Flashcards
Radioactivity
Radioactivity
The spontaneous emission of radiation from an unstable atomic nucleus.
Alpha Radiation (𝛼)
Alpha Radiation (𝛼)
The emission of alpha particles, which are clusters of two protons and two neutrons (He-4 nucleus). This results in a new element with a lower mass number.
Beta Radiation (𝛽)
Beta Radiation (𝛽)
The emission of beta particles, fast-moving electrons. The mass number remains unchanged, but the atomic number increases by 1, creating a new element.
What are the conditions for radioactivity?
What are the conditions for radioactivity?
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Why is nuclear power important?
Why is nuclear power important?
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Who discovered radioactivity?
Who discovered radioactivity?
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What is the difference between stable and radioactive isotopes?
What is the difference between stable and radioactive isotopes?
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What are the types of radioactive decay?
What are the types of radioactive decay?
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Beta Emission
Beta Emission
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Gamma Radiation
Gamma Radiation
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Ionizing Radiation
Ionizing Radiation
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Penetrating Power
Penetrating Power
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Alpha Decay
Alpha Decay
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Radioactive Decay
Radioactive Decay
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Radon Gas
Radon Gas
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Background Radiation
Background Radiation
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Rem (Radiation Equivalent Man)
Rem (Radiation Equivalent Man)
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Acute Radiation Exposure
Acute Radiation Exposure
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Half-life
Half-life
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Radiocarbon dating
Radiocarbon dating
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Carbon-14
Carbon-14
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Technetium-99m
Technetium-99m
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Positron Emission Tomography (PET)
Positron Emission Tomography (PET)
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Positron
Positron
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Nuclear fission
Nuclear fission
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Chain reaction
Chain reaction
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Uranium-235
Uranium-235
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Isotope enrichment
Isotope enrichment
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Gaseous Centrifugation
Gaseous Centrifugation
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Nuclear power
Nuclear power
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Nuclear Waste
Nuclear Waste
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What is radioactivity?
What is radioactivity?
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Types of Radioactive Decay
Types of Radioactive Decay
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Alpha Radiation
Alpha Radiation
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Beta Radiation
Beta Radiation
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What is nuclear power?
What is nuclear power?
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Nuclear Power's Contribution
Nuclear Power's Contribution
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Radioactivity's Discovery
Radioactivity's Discovery
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What does '-1' in '-10β' indicate?
What does '-1' in '-10β' indicate?
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What is beta emission?
What is beta emission?
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Gamma Radiation (𝛾)
Gamma Radiation (𝛾)
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Radon Gas (Rn-222)
Radon Gas (Rn-222)
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What is Acute Radiation Exposure?
What is Acute Radiation Exposure?
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What is the unit of ionizing radiation?
What is the unit of ionizing radiation?
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Study Notes
Course Information
- Course Title: The Chemistry of Life
- Course Code: UGEB2380
- Academic Year: 2024-25
- Instructor: Dr. Sam CK HAU (Department of Chemistry)
Nuclear Chemistry and Energy from Electron Transfer
Nuclear Power
- Significant portion of daily electricity comes from nuclear power
- In the US, 100 nuclear reactors in 30 states provide ~20% of electricity
Radioactivity
- Discovered by Antoine Henri Becquerel in 1896
- Uranium emits X-rays
- Marie Curie, his student, investigated and named the phenomenon "radioactivity"
- Emission of radiation from spontaneous decay of unstable atomic nuclei
Two Conditions Underlying Radioactivity
- Radioactive nuclei contain 84 or more protons
- Ratio of neutrons to protons in radioactive nuclei is either above or below a stable range
- Examples:
- C14: 8n & 6p (radioactive)
- C13: 7n & 6p (stable)
- C12: 6n & 6p (stable)
- C11: 5n & 6p (radioactive)
Types of Radioactive Decay
- Ernest Rutherford identified α (alpha) and β (beta) radiation
- Paul Villard discovered γ (gamma) radiation
Alpha Radiation
- Discharge of α-particles (clusters of 2 protons & 2 neutrons)
- Equivalent to He-4 nuclei
- Always changes the radioactive element into a new one
- Example of decay:
- 238U → 234Th + 4He
Beta Radiation
- Spontaneous discharge of β-particles (fast-moving electrons)
- Mass number remains unchanged but atomic number increases by 1
- Generates a new element
- Represented as β⁻; -1 indicates single negative charge
- Example of decay:
- 14C → 14N + β⁻
Gamma Radiation
- Electromagnetic radiation with higher energy than X-rays
- Can penetrate deeply into matter and cause biological harm
- Emitted during the relaxation of excited nuclei.
- Denoted as γ; no mass or electrical charge
Ionising Radiation
- α, β, and γ rays expel electrons from atoms and molecules, creating ions
- These ions, in living tissues, convert to free radicals (highly reactive molecules with unpaired electrons)
- Can damage cells and tissues
Penetrating Power
- α particles are easily stopped by paper
- β particles are stopped by aluminum foil
- γ rays easily pass through most substances and require thick lead or concrete for blocking
- Penetrating power is inversely related to the ionizing power (higher penetrating power, lower ionizing power)
Radioactive Decay - Radon
- Colourless, odourless noble gas
- Rn-222 isotope decays into polonium (Po-218)
- Radon buildup in lungs generates minuscule amounts of polonium and other radioactive isotopes, causing biological damage (including lung cancer)
- Background radiation is low-level radiation due to natural sources.
Background Radiations
- Rem is a unit of ionizing radiation (equivalent to humans)
- Average radiation exposure in the US: ~600 mrem (0.6 rem) per year (half from background)
- Cosmic radiation enters Earth from space
- Potassium-40 and radioactive isotopes like Ra, U, Po in soils emit α, β, and γ rays.
Acute Exposure to Radiation
- Large doses (>50 rem) of ionizing radiation can transform cellular molecules into harmful forms
- Can lead to somatic damage (fatigue, reduced white blood cells, damage to organs, glands, bone marrow, leukaemia, or other cancers, even genetic damage).
- Example: Alexander Litvinenko, poisoned with polonium-210
Half-life
- Time required for half of a radioactive isotope to decay.
- Different isotopes have characteristic half-lives.
- Example: Polonium-210 has a half-life of 138 days.
Radiocarbon Dating
- Carbon-14 has a half-life of 5730 years used to determine the age of once-living things.
- Useful in archeology and art history
Other Applications
- Medical: Technetium-99m (99mTc) used in imaging diagnostics for organs. It emits γ rays and exits the body quickly. Half-life: ~6 hours.
- Positron Emission Tomography (PET): Uses positron-emitting isotopes (like carbon-11). Positrons annihilate with electrons, producing γ rays, used to diagnose or treat brain abnormalities.
- Gamma Knife Radiosurgery: Concentrated γ rays from cobalt-60 to precisely target tumours.
Unleashing the Power of Nucleus
- Nuclear Fission: Splitting a heavy nucleus (e.g., uranium-235) into smaller fragments, releasing energy. Discovered by Otto Hahn and Lise Meitner (1944).
- One U-235 nucleus absorbs a neutron, splits into krypton-92 (Kr-92) and barium-141 (Ba-141) and releases three more neutrons
Nuclear Fission (Chain Reaction)
- Fission releases neutrons that can initiate further fission events
- Creates a chain reaction, releasing lots of energy
Isotope Enrichment
- Naturally occurring uranium mostly contains U-238, but fission (energy release) occurs more effectively with U-235.
- Separating U-235 from U-238 is challenging. Processes involve gaseous diffusion and gas centrifuging.
Nuclear Power (Gaseous Centrifugation)
- Molecules of UF6 (Uranium hexafluoride) with different uranium isotopes (U-235 or U-238) have slightly different masses
- Gas centrifuges separate these molecules
- Repeated process to greatly concentrate U-235
Nuclear Power (Production)
- Fission instantly releases energy
- Designed to control this process, with high-efficiency conversion to steam turning turbine for electricity generation.
Nuclear Waste
- Consists of radioactive isotopes and residual nuclear fuel.
- Hazardous, but usually below useful levels
- Some remain dangerous for a long time due to their long half-lives
- Vitrified (fused with glass) and stored deep underground
Nuclear Power (Safety)
- Accidents: Three Mile Island (1979), Chernobyl (1986), and Fukushima (2011)
- Long lead time to build new plants (~20 years or more)
Nuclear Fusion
- Light nuclei fuse, releasing energy (e.g., hydrogen fusing to form helium, typical of the sun).
- Reverse of fission
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Description
Test your knowledge on nuclear physics with this engaging quiz. Covering topics such as radioactivity, types of radiation, and historic discoveries, this quiz will challenge your understanding of fundamental concepts in nuclear science.
