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Questions and Answers
What type of electromagnetic radiation includes gamma rays and x-rays?
What type of electromagnetic radiation includes gamma rays and x-rays?
Which of the following particles is not found in the nuclei of all atoms?
Which of the following particles is not found in the nuclei of all atoms?
What is the significance of the equation E = mc² in the context of radiation?
What is the significance of the equation E = mc² in the context of radiation?
Which type of radiation is characterized by having insufficient energy to ionize atoms?
Which type of radiation is characterized by having insufficient energy to ionize atoms?
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Which type of ionizing radiation consists of two protons and two neutrons?
Which type of ionizing radiation consists of two protons and two neutrons?
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Which type of electromagnetic radiation has photons with the highest energy?
Which type of electromagnetic radiation has photons with the highest energy?
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What is the primary application of gamma rays in imaging?
What is the primary application of gamma rays in imaging?
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What does the energy of a photon depend on according to the formula E = hf?
What does the energy of a photon depend on according to the formula E = hf?
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Which characteristic distinguishes ionizing radiation from non-ionizing radiation?
Which characteristic distinguishes ionizing radiation from non-ionizing radiation?
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Which of the following electromagnetic radiations is used in computed tomography (CT) imaging?
Which of the following electromagnetic radiations is used in computed tomography (CT) imaging?
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Which of the following characteristics does electromagnetic radiation NOT possess?
Which of the following characteristics does electromagnetic radiation NOT possess?
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What is the wavelength range for gamma rays compared to visible light?
What is the wavelength range for gamma rays compared to visible light?
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How is the energy of a photon related to its frequency?
How is the energy of a photon related to its frequency?
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Which type of radiation is considered non-ionizing?
Which type of radiation is considered non-ionizing?
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What relationship holds true between speed, wavelength, and frequency for electromagnetic waves?
What relationship holds true between speed, wavelength, and frequency for electromagnetic waves?
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Which of the following statements about electromagnetic radiation is false?
Which of the following statements about electromagnetic radiation is false?
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What does the phase constant (ϕ) in the sinusoidal wave function represent?
What does the phase constant (ϕ) in the sinusoidal wave function represent?
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In the sinusoidal wave function, what does the variable 'A' represent?
In the sinusoidal wave function, what does the variable 'A' represent?
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What characteristic of electromagnetic waves allows them to change trajectory when interacting with matter?
What characteristic of electromagnetic waves allows them to change trajectory when interacting with matter?
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What is the wavelength range of infrared waves?
What is the wavelength range of infrared waves?
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Which electromagnetic waves are primarily used in radar systems?
Which electromagnetic waves are primarily used in radar systems?
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What is the main source of ultraviolet light that reaches the Earth?
What is the main source of ultraviolet light that reaches the Earth?
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What is a common application of X-rays in medicine?
What is a common application of X-rays in medicine?
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Which type of electromagnetic radiation poses a high risk of damage to living tissue when absorbed?
Which type of electromagnetic radiation poses a high risk of damage to living tissue when absorbed?
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What type of particles are emitted during radioactive decay that are positively charged?
What type of particles are emitted during radioactive decay that are positively charged?
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Which statement regarding electromagnetic radiation is false?
Which statement regarding electromagnetic radiation is false?
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How is particulate radiation fundamentally different from electromagnetic radiation?
How is particulate radiation fundamentally different from electromagnetic radiation?
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In the context of radiation, what does the equation E = mc² illustrate?
In the context of radiation, what does the equation E = mc² illustrate?
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Which type of radiation is characterized by being emitted from the nuclei of radioactive atoms?
Which type of radiation is characterized by being emitted from the nuclei of radioactive atoms?
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Which of the following describes the energy contribution of a photon?
Which of the following describes the energy contribution of a photon?
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What distinguishes alpha particles from beta particles in terms of composition?
What distinguishes alpha particles from beta particles in terms of composition?
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Which characteristic is commonly associated with non-ionizing radiation compared to ionizing radiation?
Which characteristic is commonly associated with non-ionizing radiation compared to ionizing radiation?
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Which statement accurately describes the composition of the atomic nucleus?
Which statement accurately describes the composition of the atomic nucleus?
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What is the maximum number of electrons that the L shell can hold?
What is the maximum number of electrons that the L shell can hold?
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Which type of nuclear family includes nuclides with the same atomic number but different mass numbers?
Which type of nuclear family includes nuclides with the same atomic number but different mass numbers?
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What is the importance of the binding energy of an electron in an atom?
What is the importance of the binding energy of an electron in an atom?
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Which of the following statements is true regarding nuclear stability?
Which of the following statements is true regarding nuclear stability?
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What does the notation $^{A}_{Z}X$ represent in nuclear chemistry?
What does the notation $^{A}_{Z}X$ represent in nuclear chemistry?
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Which statement about electron orbits within the Bohr model is correct?
Which statement about electron orbits within the Bohr model is correct?
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Flashcards
Ionizing Radiation
Ionizing Radiation
Radiation with enough energy to remove electrons from atoms, creating charged particles.
Nonionizing Radiation
Nonionizing Radiation
Radiation that doesn't have enough energy to remove electrons from atoms.
Alpha Particles
Alpha Particles
Particulate radiation consisting of two protons and two neutrons.
Beta Particles
Beta Particles
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Mass-Energy Equivalence
Mass-Energy Equivalence
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Photon Energy Equation
Photon Energy Equation
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Photon
Photon
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Electromagnetic Radiation
Electromagnetic Radiation
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Gamma Ray
Gamma Ray
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Electron Volt (eV)
Electron Volt (eV)
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EM Radiation
EM Radiation
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EM Wave Characteristics
EM Wave Characteristics
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EM Wavelength Units
EM Wavelength Units
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EM Frequency Units
EM Frequency Units
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Sinusoidal Wave Function
Sinusoidal Wave Function
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What is the relationship between wavelength, frequency, and speed of EM waves?
What is the relationship between wavelength, frequency, and speed of EM waves?
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What are the units for EM wavelength and frequency?
What are the units for EM wavelength and frequency?
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EM Spectrum
EM Spectrum
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Visible Light Range
Visible Light Range
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What makes different EM waves?
What makes different EM waves?
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Infrared Waves
Infrared Waves
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Ultraviolet Light
Ultraviolet Light
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Atomic Nucleus
Atomic Nucleus
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Atomic Number (Z)
Atomic Number (Z)
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Mass Number (A)
Mass Number (A)
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Isotopes
Isotopes
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Binding Energy
Binding Energy
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Ground State
Ground State
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Excited State
Excited State
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What is Mass-Energy Equivalence?
What is Mass-Energy Equivalence?
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What are the properties of Particulate Radiation?
What are the properties of Particulate Radiation?
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What is the speed of light in a vacuum?
What is the speed of light in a vacuum?
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Study Notes
Electromagnetic (EM) Radiation
- EM radiation includes visible light, radio waves, and X-rays
- It has no mass and isn't affected by electric or magnetic fields
- Travels at a constant speed in a given medium
- Travels in straight lines, but its trajectory can be altered by interacting with matter
- Absorption reduces radiation
- Scattering changes radiation's trajectory
EM Wave Characteristics
- EM waves are characterized by amplitude, wavelength (λ), frequency (f), and period (T)
- Speed (v or c), wavelength, and frequency are related by λ=vT or v = λf
- Wavelengths are typically measured in nanometers (10⁻⁹ m)
- Frequencies are expressed in hertz (Hz) (1 Hz = 1 cycle/second =1 sec⁻¹)
- For EM waves, v is the speed of light
Sinusoidal EM Wave
- EM waves oscillate in electric and magnetic fields that are perpendicular to each other and to the direction of wave travel.
- Wavelength (λ) is the distance between corresponding points on two consecutive waves.
- Amplitude is the maximum displacement from the zero position along the direction of oscillation.
- The electric and magnetic fields are 90° out of phase.
Sinusoidal Wave Function
- The sinusoidal wave function can be written as y(x, t) = A sin(kx − ωt + φ), where:
- A is the amplitude
- k is the wave number (2π/λ)
- ω is the angular frequency (2πf)
- φ is the phase constant
- It can also be expressed as a cosine function.
- In 3D, x is replaced by the position vector (x, y, z).
The Spectrum of the EM Waves
- Includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays
- Types of waves often overlap
- Distinguished by frequency or wavelength.
- Specific wavelengths correlate to specific color/radiation types
- There is a relationship between wavelength, frequency, and energy.
- Different frequencies/wavelengths are used for different applications
Notes on the EM Spectrum
- Radio waves have wavelengths greater than 10⁴ m to ~0.1 m. Used in radio & TV
- Microwaves have wavelengths from ~0.3 m to 10⁻⁴ m. Useful for radar and ovens
- Infrared wavelengths are ~10⁻³ m to 7 x 10⁻⁷ m. Produced by heat, readily absorbed by materials
- Visible light is detected by the human eye. Most sensitive to ~ 5.5 x 10⁻⁷ m (yellow-green)
- Ultraviolet light covers ~ 4 × 10⁻⁷ m to 6 × 10⁻¹⁰ m. Important radiation source from the sun and absorbed in the stratosphere by ozone
- X-rays have wavelengths ~10⁻⁸ m to 10⁻¹² m. Produced by high-energy electrons, used in medicine (diagnostic / therapeutic).
- Gamma rays have wavelengths ~10⁻¹⁰ m to 10⁻¹⁴ m. Emitted by radioactive nuclei, highly penetrating, and damaging. Used in medicine.
Particulate Radiation
- Protons: Found in nuclei of all atoms, have a single positive charge
- Electrons: Exist in atomic orbits, emitted from some radioactive atoms (beta particles ⁻)
- Positrons: Positively charged electrons (β⁺), emitted by some nuclei during radioactive decay
- Neutrons: Uncharged nuclear particles, released by nuclear fission and used for radionuclide production
Mass Energy Equivalence
- Einstein's theory of relativity: Mass and energy are interchangeable
- E = mc² (E representing energy, m representing mass, and c representing the speed of light)
Fundamental Properties of Particulate Radiation
- Table including particles (proton, electron, positron, neutron), their symbols, relative charge in multiples of the electron charge, and approximate energy in MeV.
Structure of the Atom
- Smallest division of an element with maintained chemical identity
- Composed of a dense, positively charged nucleus containing protons and neutrons, with a cloud of negatively charged electrons outside the nucleus.
- Electrically neutral in its nonionized state
Bohr Model of the Atom
- Electrons orbit a dense, positively charged nucleus at fixed distances
- Each electron occupies a discrete energy state in a given electron shell
- Shells are assigned letters (K, L, M, N...) and quantum numbers (1, 2, 3, 4...)
- Each shell can hold a maximum of (2n²) electrons, with n being the quantum number
Electron Shells
- Diagram showing electron energy levels (K, L, M, N...) around the nucleus
- Quantum number, maximum number of electron capacity
Binding Energy of Electron
- Energy required to remove an electron completely from an atom
- Conventionally negative and increases with closeness to the nucleus
- Binding energy increases with the number of protons in the nucleus (atomic number)
Atomic Nucleus
- Composed of protons and neutrons (collectively, nucleons)
- The number of protons is the atomic number (Z)
- The total number of protons and neutrons is the mass number (A)
- Notation for an atom is ᴬₓ (with chemical symbol X)
Nuclear Energy Levels
- Nuclei have energy levels analogous to electron shells
- Lowest energy state is called the ground state
- Nuclei with higher energy are in the excited state
- Excited states that last longer than 10−¹² seconds are metastable, also called isomeric states, denoted by the letter m after the mass number (e.g., Tc-99m).
Nuclear Families
- Table with categories (isotopes, isobars, isotones, and isomers) showing nuclides with similar properties
- Examples for each family
Nuclear Stability
- Only specific neutron-proton combinations are stable
- Heavy elements require a higher neutron-to-proton ratio to offset electrostatic forces between protons
- Nuclei with odd numbers of both neutrons and protons tend to be unstable
Nuclear Stability (Diagram)
- Graph showing the relationship between neutron and proton numbers in stable nuclei against unstable nuclei
Nuclear Structure
- The nucleus of an atom consists of nucleons (protons and neutrons)
- Atomic number (Z) represents the number of protons
- Nucleon number (A) represents the total number of protons and neutrons
- Notation for an atom is often expressed by the chemical symbol and nucleon number (A)
- Atoms of the same element can have different numbers of neutrons. These are called isotopes.
Nuclear Structure (Radius)
- Nuclei are clustered together to form a spherical region
- The radius of the nucleus depends on the atomic mass A by a formula (r ≈ (1.2×10⁻¹⁵ m) A^(1/3))
- Isotopes: Nuclei with the same number of protons (Z) but different mass numbers (A)
Ionizing vs. Nonionizing Radiation
- EM radiation with higher frequency than near-UV removes electrons, producing ionized atoms/molecules
- This is called ionizing radiation
- Lower-frequency radiation is non-ionizing (e.g., visible light)
Additional Slides (Self Study)
Radioactivity
- Unstable nuclei undergo radioactive decay to achieve stability by emitting different particles or transforming nucleons.
- Unstable nuclei change their number of protons and neutrons
- The process is accompanied by the emission of energy.
- The emission can be particulate or electromagnetic.
Alpha Decay
- An alpha particle is a helium nucleus (²⁴He)
- It has a charge of +2e and a nucleon number of 4
- Alpha decay involves the emission of an alpha particle and the release of energy (kinetic energy) shared between the alpha particle and recoiling daughter nucleus
Alpha Decay (calculations)
- Mass conservation is imperative in alpha decay; the total initial mass before decay equals the total mass after decay. There is slight mass difference that represents released binding energy
Beta Decay
- A beta particle is an electron (⁻₁e) with a negative charge (-e)
- Beta decay transforms a neutron into a proton (or vice-versa) which means there is a change in the number of protons in the nucleus
- Beta decay is accompanied by the emission of an antineutrino
Neutrino and Antineutrino
- Neutrinos are neutral subatomic particles with small mass and half-integral spin
- Rarely interact with normal matter
- Created in radioactive or nuclear reactions, as well as when cosmic rays hit atoms.
- Antineutrinos are the antiparticles of neutrinos
- Emitted during beta decay.
Beta+ Decay
- Beta particle is a positron (+₁e) with a positive charge (+e)
- Beta plus decay converts a proton in a nucleus to a neutron
- Accompanied by emission of a neutrino
Beta+ Decay (Medical Applications)
- Positron emitters are used in PET scans for functional imaging
- A positron emitter radionuclide is injected into an area and accumulates in a tissue
- Positrons undergo annihilation with electrons, resulting in two gamma photons emitted at opposite directions which are detected for diagnostic purposes.
Electron Capture
- An orbital electron (from inner shells, K or L) is captured by a proton in the nucleus
- This process forms a neutron
- Accompanied by emission of a neutrino
Gamma Decay
- EM radiation emitted as the nucleus goes from one excited state to a lower energy state/ground state
- Also produced if the nucleus is in a metastable excited state (isomeric state), the decay is called an Isomeric Transition
- Gamma decay involves no change in the number of protons or neutrons in the nucleus
Internal Conversion Electrons
- Alternative to gamma emission, internal conversion electrons are emitted when orbital electrons absorb the energy from the nucleus transitioning to a lower energy state, causing the ejection of an electron from the atom
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Description
This quiz covers the fundamental concepts of electromagnetic radiation, including its properties, types, and wave characteristics. Understand how EM waves travel, their measurable attributes, and the relationship between wavelength and frequency.
