light (1).pptx
•Download as PPTX, PDF•
0 likes•81 views
1. Light can be described as both waves and particles. The photoelectric effect provided evidence that light behaves as particles called photons. 2. When light shines on certain materials, electrons are emitted. Einstein explained this using a quantum theory where light is made of discrete photon particles that eject electrons when they collide with the material. 3. The energy of photons depends on their frequency, not amplitude. A minimum photon frequency is needed to eject electrons, showing light has quantized energies. This discovery supported the photon model of light and was a landmark in the development of quantum theory.
Report
Share
Report
Share
Recommended
Particle Properties of Wave
This document discusses various topics related to the particle properties of waves, including:
- The photoelectric effect and how photons carry energy in quantized packets.
- Max Planck's quantum hypothesis which established that electromagnetic wave energy is quantized in units of hf.
- Wave-particle duality and how light exhibits both wave and particle behaviors.
- X-rays and how they are produced via the inverse photoelectric effect when electrons are accelerated and strike a metal target.
- The Compton effect which demonstrates that photons can transfer energy and momentum to electrons during scattering.
- Photons, the basic unit of light and electromagnetic radiation which have zero mass but carry energy proportional to their frequency
Waves and Light
Waves and light are discussed, including characteristics of waves, the nature of light, and its speed of 3x10^8 m/s. Light behaves as both a wave and particle - as an electromagnetic wave with electric and magnetic fields, and as photons. The photoelectric effect is explained as the ejection of electrons from surfaces illuminated by ultraviolet light.
Magnetism
This document provides an overview of magnetism and electromagnetism. It discusses magnetic poles and fields, induced magnetism through electromagnetic induction, and how generators produce alternating current. Moving a magnet or conductor in a magnetic field can induce electric currents according to Faraday's law of induction. The strength of magnetic fields depends on factors like the current flowing and number of wire loops or turns.
Vu4 light&matter2009
This document provides an outline for Unit 4 Topic 2 on interactions of light and matter in VCE Physics. It lists key learning outcomes including explaining various phenomena through wave and particle models of light such as the production of incoherent light, Young's double slit experiment, diffraction, the photoelectric effect, electron diffraction, and atomic spectra. Chapter 1 covers the nature of light as electromagnetic radiation and concepts of interference, incoherent versus coherent light sources, and Young's experiment demonstrating the wave-like properties of light. Incandescent light sources produce incoherent light from the random thermal excitation of electrons.
Ch 29 Particles and Waves
The document discusses key concepts in atomic and nuclear physics including:
1) Photons and their properties such as energy, momentum, and relation to wavelength and frequency. The photoelectric effect and how it provided evidence for photons.
2) Compton scattering and how it showed that light has particle-like properties. The nature and production of x-rays.
3) Wave-particle duality and concepts like de Broglie wavelength which showed matter has wave-like properties. Key experiments that demonstrated these dual properties.
PHOTOELECTRIC EFFECT
- Heinrich Hertz observed electromagnetic waves in 1887 using a coil and spark gap receiver. Removing the apparatus from a darkened box increased the maximum spark length observed.
- In 1905, Einstein published his paper explaining the photoelectric effect using the theory that light is quantized into discrete photon packets. His equation related the energy of photons to the kinetic energy of emitted electrons.
- The photoelectric effect has applications in devices like solar panels, photoelectric smoke detectors, and night vision goggles.
Photoelectric effect ppt
This document discusses evidence for both the wave and particle nature of light. For the wave nature, it mentions phenomena like reflection, refraction, diffraction, and interference that were observed in experiments. For the particle nature, it discusses observations that supported Planck's quantization of energy and Einstein's model of light as discrete photon particles, including the photoelectric effect, atomic spectra, and blackbody radiation. The photoelectric effect in particular provided strong evidence that light behaves as a particle by instantaneously ejecting electrons from metals above a threshold frequency, rather than depending on intensity as waves were thought to. This helped establish the dual wave-particle nature of light.
Wave particle duality of light- A changing Notion in Science
Here a changing notion of science has been displayed. How the concept of wave theory of light changed to particle theory and finally the duality.
Recommended
Particle Properties of Wave
This document discusses various topics related to the particle properties of waves, including:
- The photoelectric effect and how photons carry energy in quantized packets.
- Max Planck's quantum hypothesis which established that electromagnetic wave energy is quantized in units of hf.
- Wave-particle duality and how light exhibits both wave and particle behaviors.
- X-rays and how they are produced via the inverse photoelectric effect when electrons are accelerated and strike a metal target.
- The Compton effect which demonstrates that photons can transfer energy and momentum to electrons during scattering.
- Photons, the basic unit of light and electromagnetic radiation which have zero mass but carry energy proportional to their frequency
Waves and Light
Waves and light are discussed, including characteristics of waves, the nature of light, and its speed of 3x10^8 m/s. Light behaves as both a wave and particle - as an electromagnetic wave with electric and magnetic fields, and as photons. The photoelectric effect is explained as the ejection of electrons from surfaces illuminated by ultraviolet light.
Magnetism
This document provides an overview of magnetism and electromagnetism. It discusses magnetic poles and fields, induced magnetism through electromagnetic induction, and how generators produce alternating current. Moving a magnet or conductor in a magnetic field can induce electric currents according to Faraday's law of induction. The strength of magnetic fields depends on factors like the current flowing and number of wire loops or turns.
Vu4 light&matter2009
This document provides an outline for Unit 4 Topic 2 on interactions of light and matter in VCE Physics. It lists key learning outcomes including explaining various phenomena through wave and particle models of light such as the production of incoherent light, Young's double slit experiment, diffraction, the photoelectric effect, electron diffraction, and atomic spectra. Chapter 1 covers the nature of light as electromagnetic radiation and concepts of interference, incoherent versus coherent light sources, and Young's experiment demonstrating the wave-like properties of light. Incandescent light sources produce incoherent light from the random thermal excitation of electrons.
Ch 29 Particles and Waves
The document discusses key concepts in atomic and nuclear physics including:
1) Photons and their properties such as energy, momentum, and relation to wavelength and frequency. The photoelectric effect and how it provided evidence for photons.
2) Compton scattering and how it showed that light has particle-like properties. The nature and production of x-rays.
3) Wave-particle duality and concepts like de Broglie wavelength which showed matter has wave-like properties. Key experiments that demonstrated these dual properties.
PHOTOELECTRIC EFFECT
- Heinrich Hertz observed electromagnetic waves in 1887 using a coil and spark gap receiver. Removing the apparatus from a darkened box increased the maximum spark length observed.
- In 1905, Einstein published his paper explaining the photoelectric effect using the theory that light is quantized into discrete photon packets. His equation related the energy of photons to the kinetic energy of emitted electrons.
- The photoelectric effect has applications in devices like solar panels, photoelectric smoke detectors, and night vision goggles.
Photoelectric effect ppt
This document discusses evidence for both the wave and particle nature of light. For the wave nature, it mentions phenomena like reflection, refraction, diffraction, and interference that were observed in experiments. For the particle nature, it discusses observations that supported Planck's quantization of energy and Einstein's model of light as discrete photon particles, including the photoelectric effect, atomic spectra, and blackbody radiation. The photoelectric effect in particular provided strong evidence that light behaves as a particle by instantaneously ejecting electrons from metals above a threshold frequency, rather than depending on intensity as waves were thought to. This helped establish the dual wave-particle nature of light.
Wave particle duality of light- A changing Notion in Science
Here a changing notion of science has been displayed. How the concept of wave theory of light changed to particle theory and finally the duality.
Ppt
This document discusses the dual wave-particle nature of X-rays and their interaction with matter. It notes that X-rays can behave as both waves that propagate through space, as well as particles called photons. The two main interactions discussed are the photoelectric effect and Compton scattering.
The photoelectric effect occurs when a photon ejects an inner shell electron from an atom. This produces characteristic radiation, a photoelectron, and an ionized atom. It is most likely with low-energy photons and high atomic number elements. Compton scattering occurs when a high-energy photon ejects a loosely bound outer shell electron. This produces a recoil electron and scattered photon, with energy distributed between the two. Scattered photons are
Grade12, U9-L2 Photoelectric Effect
1) The document discusses the quantum theory of light and the photoelectric effect. It describes experiments by Lenard and Einstein's explanation of the photoelectric effect using the idea that light is composed of quanta called photons.
2) Einstein proposed that photons transfer all of their energy to electrons in packets. Higher frequency photons transfer more energy, allowing electrons to escape metals with higher kinetic energy.
3) The maximum kinetic energy of photoelectrons depends on the photon frequency and the work function of the metal, with the work function representing the minimum energy needed to remove an electron from the metal.
Dual nature of matter and radiations
1) The document discusses the dual nature of matter and light, explaining that light has both wave-like and particle-like properties, as demonstrated through the photoelectric effect.
2) It introduces Einstein's photoelectric equation, which relates the maximum kinetic energy of emitted electrons to the photon energy of the incident light according to the conservation of energy.
3) Experiments by Davison and Germer are discussed, in which they observed the diffraction of electrons fired at a crystal, providing evidence that matter also exhibits wave-like properties as described by the de Broglie hypothesis of matter waves.
Light dualism
The document discusses the dual wave-particle nature of light and photons. It explains that light exhibits both wave features like frequency and wavelength, as well as particle features like energy and momentum. The document also discusses Compton scattering, where photons transfer some of their energy to electrons, increasing their wavelength. Additionally, it covers de Broglie's proposal that matter has both wave and particle properties, and introduces the concept of de Broglie wavelength for particles like electrons.
8th Grade Chapter 2 Lesson 1
Light can be described as a wave or a particle. As a wave, light is made up of oscillating electric and magnetic fields that propagate as electromagnetic waves. Electromagnetic waves include radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays. Visible light is a small portion of the electromagnetic spectrum. As a particle, light exists as discrete packets of energy called photons, with the energy of each photon depending on the wavelength and frequency of the electromagnetic wave.
C24 quantization-of-light
This document provides an overview of Planck's quantum theory and the photoelectric effect. It begins by outlining the key learning outcomes for understanding Planck's quantum theory, which distinguished energy of electromagnetic radiation as quantized rather than continuous. It then describes the photoelectric effect and defines important concepts like work function and stopping potential. Finally, it presents Einstein's explanation of the photoelectric effect using photon energy and provides examples demonstrating how to use the photoelectric equations.
Wave particle duality
Wave-particle duality postulates that all particles exhibit both wave and particle properties under different experimental conditions. Historically, debates centered around whether light was a wave or particle. Key experiments and theorists helped establish the dual nature of light and matter, including:
- Einstein showing light has particle-like photons; Compton effect confirming this.
- De Broglie proposing electrons and matter have wave properties like wavelength and frequency. Davisson and Germer experimentally verified the wave nature of electrons.
- The double slit experiment demonstrated the wave behavior of electrons through an interference pattern, shocking as electrons were considered particles. This supported matter having wave-particle duality.
Photo electric effect
The document summarizes the photoelectric effect, which is the ejection of electrons from a metal surface when light of a suitable frequency strikes it. It explains that the photoelectric effect supports the particle theory of light. It provides the typical experimental setup, relationships between the energy of photons and kinetic energy of emitted electrons, and current and applied potential difference. It also outlines the laws of the photoelectric effect and Einstein's equation relating the maximum kinetic energy of electrons to the photon energy and metal's work function.
The compton effect
The Compton effect occurs when a high-energy photon collides with an electron, causing the photon to lose some energy and increase in wavelength. Arthur Holly Compton discovered this effect in 1923 through experiments bombarding a graphite target with x-rays and measuring the wavelength of scattered radiation. The effect showed that light behaves as both a particle and wave and is important in fields like radiation therapy and gamma spectroscopy. It is explained by the transfer of momentum and energy between the photon and electron during collision.
Interaction Between Matter and X ray
X-rays can interact with matter through various interactions including the photoelectric effect, Compton scattering, and coherent scattering. The photoelectric effect and Compton scattering are the most important interactions in diagnostic radiology. Scatter radiation is a major source of reduced image quality and increased patient dose in x-rays, and various techniques like grids and filters are used to control scatter.
The Photoelectric Effect lab report
Ethan conducted a photoelectric effect experiment to calculate Planck's constant. The experiment involved measuring the stopping potential of electrons emitted from a metal surface under monochromatic light of varying wavelengths. Plotting average stopping potential versus the reciprocal of wavelength produced a straight line, from which Planck's constant could be calculated using the slope. Ethan's calculated value of Planck's constant had a 36% error compared to the accepted value, which was within an acceptable range for the experiment.
6 Pius Augustine Photoelectric Effect
The document is a presentation by Dr. Pius Augustine on the photoelectric effect. It contains:
- An overview of the photoelectric effect and its discovery.
- Descriptions and explanations of the laws of photoelectric emission based on experimental observations.
- How Einstein's photon theory and quantum interpretation provided explanations that classical theories could not.
- Examples of calculations and problems demonstrating applications of photoelectric concepts and equations.
The presentation provides a comprehensive overview of the photoelectric effect from its discovery to its explanation via Einstein's photon theory and the role it played in establishing the foundation of quantum mechanics.
Photoelectric effect and experimental setup
Group D7 has 5 members from different batches: Omkar Rane, Prashant Mungase, Mehul Joshi, Jamir Sheikh, and Vikram Kare.
The document then discusses the timeline of developments in understanding the photoelectric effect. It describes early observations by Heinrich Hertz in 1887, definitive studies by Philipp Lenard in the 1890s, and Albert Einstein's 1905 paper explaining that light behaves as discrete packets of energy called photons.
VCE Physics Unit 3: Electronics & Photonics Base notes
This document provides an overview of key concepts in electronics and photonics covered in a VCE Physics Unit 3 topic. It discusses:
- Applying concepts such as current, resistance, voltage and power to electronic circuits including diodes, resistors, thermistors, light dependent resistors, photodiodes and LEDs.
- Calculating effective resistance of parallel and series circuits and voltage dividers.
- Describing energy transfers in opto-electronic devices and information transfer using light intensity modulation and demodulation.
- Designing, analyzing and investigating circuits for specific purposes using specifications for electronic components.
- Analyzing voltage characteristics of amplifiers and identifying safe practices for electrical and photonic equipment.
PHOTOELECTRIC EFFECT
The document discusses the photoelectric effect and its applications. It begins by explaining Einstein's theory that light consists of quantized packets of energy called photons and how this explains the photoelectric effect. It then discusses how the kinetic energy of emitted electrons increases with higher frequency light. The document also provides a simple diagram of a photoelectric experiment and describes some common applications of the effect, including night vision devices, cameras, and smoke detectors. It ends by showing an image and further explaining how photoelectric smoke detectors work by detecting light scattered by smoke particles.
Photoelectric effect ppt
The photoelectric effect occurs when light irradiates a metal surface, causing electrons to be emitted. It was discovered in 1887 by Hertz but was later explained by Einstein, who proposed that light is made up of discrete particle-like packets called photons. For a given metal, there is a minimum photon frequency, called the threshold frequency, required to cause electron emission. The kinetic energy of emitted electrons depends on the photon frequency and the metal's work function.
Photoelectric Effect
The document discusses the photoelectric effect and how it helped lead to Einstein's fame. It describes experiments showing that shining blue light on a metal foil causes electrons to be emitted, while red light does not. Increasing the intensity of red light also does not cause emission. Einstein explained these results by proposing that light consists of discrete quanta of energy, with higher frequency light having more energy per quantum. His theory that the energy of emitted electrons depends on the frequency, not intensity, of light helped establish the quantum nature of light.
Nature of light (edexcel AS levels)
Advanced level excel AS level Nature of light topic in an easy way of understanding
reach
www.fixurscore.com for more things
Chapter 3 photoelectric effect
The document discusses the photoelectric effect and provides details on several key topics:
1. It outlines 5 main subtopics to be covered in the chapter, including how the intensity and frequency of light affects photoelectrons and the quantitative equations involved.
2. It describes the photoelectric effect as the emission of electrons from a metal surface when light shines on it. Experimental results showed inconsistencies with the wave theory of light.
3. Einstein's photon theory predicted the kinetic energy of ejected electrons would increase linearly with frequency, in agreement with experiments, resolving discrepancies with the wave theory.
Wave particle duality
This document discusses the wave-particle duality of light and matter. It explains how experiments demonstrating the photoelectric effect and electron diffraction show that electromagnetic radiation and electrons exhibit both wave-like and particle-like properties depending on the situation. De Broglie hypothesized that all particles can behave as waves, and he formulated an equation showing that particles are associated with a wavelength determined by their momentum and Planck's constant.
Subhadeep_BSPH101.pptx dsuyfgwf7ywidvweiufwetdfiuqefuhygedfiewgfi
This document discusses the photoelectric effect and its key aspects. It describes how photons eject electrons from metal surfaces when above a threshold frequency. Einstein's explanation of light as discrete photon packets with energy proportional to frequency is presented. The document outlines photon properties, the mathematical description of maximum kinetic energy of ejected electrons, and concludes that the photoelectric effect was crucial for understanding the quantum nature of light.
Photoelectric effect & quantum behavior of light
- The photoelectric effect occurs when electromagnetic radiation strikes a metal surface, causing electrons to be emitted.
- Einstein's quantum theory explained the photoelectric effect by proposing that light exists in discrete packets called photons, with each photon having an energy proportional to its frequency.
- When a photon strikes a metal surface and is absorbed by an electron, the electron receives the photon's energy. If the energy exceeds the metal's work function, the electron is ejected as a photoelectron.
More Related Content
What's hot
Ppt
This document discusses the dual wave-particle nature of X-rays and their interaction with matter. It notes that X-rays can behave as both waves that propagate through space, as well as particles called photons. The two main interactions discussed are the photoelectric effect and Compton scattering.
The photoelectric effect occurs when a photon ejects an inner shell electron from an atom. This produces characteristic radiation, a photoelectron, and an ionized atom. It is most likely with low-energy photons and high atomic number elements. Compton scattering occurs when a high-energy photon ejects a loosely bound outer shell electron. This produces a recoil electron and scattered photon, with energy distributed between the two. Scattered photons are
Grade12, U9-L2 Photoelectric Effect
1) The document discusses the quantum theory of light and the photoelectric effect. It describes experiments by Lenard and Einstein's explanation of the photoelectric effect using the idea that light is composed of quanta called photons.
2) Einstein proposed that photons transfer all of their energy to electrons in packets. Higher frequency photons transfer more energy, allowing electrons to escape metals with higher kinetic energy.
3) The maximum kinetic energy of photoelectrons depends on the photon frequency and the work function of the metal, with the work function representing the minimum energy needed to remove an electron from the metal.
Dual nature of matter and radiations
1) The document discusses the dual nature of matter and light, explaining that light has both wave-like and particle-like properties, as demonstrated through the photoelectric effect.
2) It introduces Einstein's photoelectric equation, which relates the maximum kinetic energy of emitted electrons to the photon energy of the incident light according to the conservation of energy.
3) Experiments by Davison and Germer are discussed, in which they observed the diffraction of electrons fired at a crystal, providing evidence that matter also exhibits wave-like properties as described by the de Broglie hypothesis of matter waves.
Light dualism
The document discusses the dual wave-particle nature of light and photons. It explains that light exhibits both wave features like frequency and wavelength, as well as particle features like energy and momentum. The document also discusses Compton scattering, where photons transfer some of their energy to electrons, increasing their wavelength. Additionally, it covers de Broglie's proposal that matter has both wave and particle properties, and introduces the concept of de Broglie wavelength for particles like electrons.
8th Grade Chapter 2 Lesson 1
Light can be described as a wave or a particle. As a wave, light is made up of oscillating electric and magnetic fields that propagate as electromagnetic waves. Electromagnetic waves include radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays. Visible light is a small portion of the electromagnetic spectrum. As a particle, light exists as discrete packets of energy called photons, with the energy of each photon depending on the wavelength and frequency of the electromagnetic wave.
C24 quantization-of-light
This document provides an overview of Planck's quantum theory and the photoelectric effect. It begins by outlining the key learning outcomes for understanding Planck's quantum theory, which distinguished energy of electromagnetic radiation as quantized rather than continuous. It then describes the photoelectric effect and defines important concepts like work function and stopping potential. Finally, it presents Einstein's explanation of the photoelectric effect using photon energy and provides examples demonstrating how to use the photoelectric equations.
Wave particle duality
Wave-particle duality postulates that all particles exhibit both wave and particle properties under different experimental conditions. Historically, debates centered around whether light was a wave or particle. Key experiments and theorists helped establish the dual nature of light and matter, including:
- Einstein showing light has particle-like photons; Compton effect confirming this.
- De Broglie proposing electrons and matter have wave properties like wavelength and frequency. Davisson and Germer experimentally verified the wave nature of electrons.
- The double slit experiment demonstrated the wave behavior of electrons through an interference pattern, shocking as electrons were considered particles. This supported matter having wave-particle duality.
Photo electric effect
The document summarizes the photoelectric effect, which is the ejection of electrons from a metal surface when light of a suitable frequency strikes it. It explains that the photoelectric effect supports the particle theory of light. It provides the typical experimental setup, relationships between the energy of photons and kinetic energy of emitted electrons, and current and applied potential difference. It also outlines the laws of the photoelectric effect and Einstein's equation relating the maximum kinetic energy of electrons to the photon energy and metal's work function.
The compton effect
The Compton effect occurs when a high-energy photon collides with an electron, causing the photon to lose some energy and increase in wavelength. Arthur Holly Compton discovered this effect in 1923 through experiments bombarding a graphite target with x-rays and measuring the wavelength of scattered radiation. The effect showed that light behaves as both a particle and wave and is important in fields like radiation therapy and gamma spectroscopy. It is explained by the transfer of momentum and energy between the photon and electron during collision.
Interaction Between Matter and X ray
X-rays can interact with matter through various interactions including the photoelectric effect, Compton scattering, and coherent scattering. The photoelectric effect and Compton scattering are the most important interactions in diagnostic radiology. Scatter radiation is a major source of reduced image quality and increased patient dose in x-rays, and various techniques like grids and filters are used to control scatter.
The Photoelectric Effect lab report
Ethan conducted a photoelectric effect experiment to calculate Planck's constant. The experiment involved measuring the stopping potential of electrons emitted from a metal surface under monochromatic light of varying wavelengths. Plotting average stopping potential versus the reciprocal of wavelength produced a straight line, from which Planck's constant could be calculated using the slope. Ethan's calculated value of Planck's constant had a 36% error compared to the accepted value, which was within an acceptable range for the experiment.
6 Pius Augustine Photoelectric Effect
The document is a presentation by Dr. Pius Augustine on the photoelectric effect. It contains:
- An overview of the photoelectric effect and its discovery.
- Descriptions and explanations of the laws of photoelectric emission based on experimental observations.
- How Einstein's photon theory and quantum interpretation provided explanations that classical theories could not.
- Examples of calculations and problems demonstrating applications of photoelectric concepts and equations.
The presentation provides a comprehensive overview of the photoelectric effect from its discovery to its explanation via Einstein's photon theory and the role it played in establishing the foundation of quantum mechanics.
Photoelectric effect and experimental setup
Group D7 has 5 members from different batches: Omkar Rane, Prashant Mungase, Mehul Joshi, Jamir Sheikh, and Vikram Kare.
The document then discusses the timeline of developments in understanding the photoelectric effect. It describes early observations by Heinrich Hertz in 1887, definitive studies by Philipp Lenard in the 1890s, and Albert Einstein's 1905 paper explaining that light behaves as discrete packets of energy called photons.
VCE Physics Unit 3: Electronics & Photonics Base notes
This document provides an overview of key concepts in electronics and photonics covered in a VCE Physics Unit 3 topic. It discusses:
- Applying concepts such as current, resistance, voltage and power to electronic circuits including diodes, resistors, thermistors, light dependent resistors, photodiodes and LEDs.
- Calculating effective resistance of parallel and series circuits and voltage dividers.
- Describing energy transfers in opto-electronic devices and information transfer using light intensity modulation and demodulation.
- Designing, analyzing and investigating circuits for specific purposes using specifications for electronic components.
- Analyzing voltage characteristics of amplifiers and identifying safe practices for electrical and photonic equipment.
PHOTOELECTRIC EFFECT
The document discusses the photoelectric effect and its applications. It begins by explaining Einstein's theory that light consists of quantized packets of energy called photons and how this explains the photoelectric effect. It then discusses how the kinetic energy of emitted electrons increases with higher frequency light. The document also provides a simple diagram of a photoelectric experiment and describes some common applications of the effect, including night vision devices, cameras, and smoke detectors. It ends by showing an image and further explaining how photoelectric smoke detectors work by detecting light scattered by smoke particles.
Photoelectric effect ppt
The photoelectric effect occurs when light irradiates a metal surface, causing electrons to be emitted. It was discovered in 1887 by Hertz but was later explained by Einstein, who proposed that light is made up of discrete particle-like packets called photons. For a given metal, there is a minimum photon frequency, called the threshold frequency, required to cause electron emission. The kinetic energy of emitted electrons depends on the photon frequency and the metal's work function.
Photoelectric Effect
The document discusses the photoelectric effect and how it helped lead to Einstein's fame. It describes experiments showing that shining blue light on a metal foil causes electrons to be emitted, while red light does not. Increasing the intensity of red light also does not cause emission. Einstein explained these results by proposing that light consists of discrete quanta of energy, with higher frequency light having more energy per quantum. His theory that the energy of emitted electrons depends on the frequency, not intensity, of light helped establish the quantum nature of light.
Nature of light (edexcel AS levels)
Advanced level excel AS level Nature of light topic in an easy way of understanding
reach
www.fixurscore.com for more things
Chapter 3 photoelectric effect
The document discusses the photoelectric effect and provides details on several key topics:
1. It outlines 5 main subtopics to be covered in the chapter, including how the intensity and frequency of light affects photoelectrons and the quantitative equations involved.
2. It describes the photoelectric effect as the emission of electrons from a metal surface when light shines on it. Experimental results showed inconsistencies with the wave theory of light.
3. Einstein's photon theory predicted the kinetic energy of ejected electrons would increase linearly with frequency, in agreement with experiments, resolving discrepancies with the wave theory.
Wave particle duality
This document discusses the wave-particle duality of light and matter. It explains how experiments demonstrating the photoelectric effect and electron diffraction show that electromagnetic radiation and electrons exhibit both wave-like and particle-like properties depending on the situation. De Broglie hypothesized that all particles can behave as waves, and he formulated an equation showing that particles are associated with a wavelength determined by their momentum and Planck's constant.
What's hot (20)
VCE Physics Unit 3: Electronics & Photonics Base notes
VCE Physics Unit 3: Electronics & Photonics Base notes
Similar to light (1).pptx
Subhadeep_BSPH101.pptx dsuyfgwf7ywidvweiufwetdfiuqefuhygedfiewgfi
This document discusses the photoelectric effect and its key aspects. It describes how photons eject electrons from metal surfaces when above a threshold frequency. Einstein's explanation of light as discrete photon packets with energy proportional to frequency is presented. The document outlines photon properties, the mathematical description of maximum kinetic energy of ejected electrons, and concludes that the photoelectric effect was crucial for understanding the quantum nature of light.
Photoelectric effect & quantum behavior of light
- The photoelectric effect occurs when electromagnetic radiation strikes a metal surface, causing electrons to be emitted.
- Einstein's quantum theory explained the photoelectric effect by proposing that light exists in discrete packets called photons, with each photon having an energy proportional to its frequency.
- When a photon strikes a metal surface and is absorbed by an electron, the electron receives the photon's energy. If the energy exceeds the metal's work function, the electron is ejected as a photoelectron.
Particle Properties of Waves
This document discusses the development of quantum mechanics. It summarizes that classical physics could not explain certain experimental observations, leading to quantum theory. Key events were Planck's blackbody radiation law, Einstein's explanation of the photoelectric effect using light quanta (photons), and Compton's discovery that photons transfer momentum to electrons. The photoelectric effect showed that light behaves as particles (photons), while the de Broglie hypothesis and Davisson-Germer experiment showed that electrons can behave as waves. This established the wave-particle duality of both light and matter.
052516 week11 quantum2
Quantum mechanics describes the motion of particles at the atomic scale. Albert Einstein's explanation of the photoelectric effect showed that light behaves as particles called photons. The photoelectric effect demonstrates that electrons can be emitted from metals when light of a high enough frequency strikes the surface. Kinetic energy of emitted electrons is determined by the frequency of light and the work function of the metal. This supported the idea that light has both wave-like and particle-like properties, leading to the development of electron microscopes that use electrons' wave-like behavior.
13.1
1. The document discusses the photoelectric effect and how it contradicted classical physics predictions but aligned with Einstein's explanation using quantum theory.
2. Einstein proposed that light behaves as discrete packets of energy called photons, and that photons can eject electrons from a metal surface if they have sufficient energy to overcome the metal's work function.
3. Experiments validated Einstein's explanation by showing that photoelectrons are ejected instantly dependent on photon frequency, not intensity, and with a range of kinetic energies.
Quantum mechanics S5
1) Classical mechanics and Maxwell's equations can explain macroscopic phenomena but quantum mechanics is needed to explain microscopic phenomena such as atomic structure.
2) Quantum mechanics arose from the need to explain physical phenomena not accounted for by classical physics, including blackbody radiation, the photoelectric effect, atomic spectra, and specific heat of solids.
3) Experiments such as the photoelectric effect, Compton effect, diffraction of electrons demonstrated that particles have wave-like properties and waves have particle-like properties, showing the need for a new theoretical framework that incorporated wave-particle duality.
B.Tech sem I Engineering Physics U-IV Chapter 1-ATOMIC PHYSICS
Atomic physics describes phenomena at the scale of atoms and subatomic particles. It emerged in the early 20th century to address limitations in classical physics' ability to describe certain phenomena. Quantum physics recognizes that there is less difference between waves and particles than previously thought. It is probabilistic and counterintuitive, describing particles that can behave as waves and vice versa. Quantum physics underlies our understanding of atomic and subatomic systems and is crucial to fields like chemistry, materials science, and astrophysics. Planck's quantum hypothesis proposed that atoms can only absorb or emit energy in discrete quanta, initiating the development of quantum theory. Einstein later theorized that electromagnetic radiation consists of discrete photon particles, helping explain the photoelectric effect.
Modern_Physics,_Photoelectric_Effect_&_X_rays_BOUNCE_BACK_24_DEC (1).pdf
Ajit Lulla is an expert physics faculty with over 11 years of experience teaching at IIT Bombay and Allen Career Institute. He has helped many students achieve top ranks in JEE and NEET, with some students ranking as high as AIR 69, 81, and 121. AT24 offers unlimited access to Ajit Lulla's structured courses, personalized guidance, test analysis, specialized study material, a customized study planner with bi-weekly reviews, and study booster workshops led by exam experts.
Dual Nature of Radiation
This document summarizes the photoelectric effect and Einstein's explanation of it. It describes experiments showing that electrons are emitted from metals when illuminated with light above a threshold frequency. The wave theory of light could not explain these observations. Einstein explained that light consists of discrete quanta called photons. When photons collide with electrons, they transfer their full energy instantly. If the photon energy exceeds the metal's work function, the electron gains enough energy to escape. Einstein's equation relates the photon's energy to the electron's maximum kinetic energy.
Chapter basic of quantum mechanics
1) The document discusses the photoelectric effect and early explanations provided by Planck's quantum theory and Einstein. It describes experiments showing that electrons are emitted from metals when light above a threshold frequency strikes them.
2) Einstein used Planck's idea that energy is emitted and absorbed in discrete quanta to explain the photoelectric effect. He proposed that light consists of discrete packets of energy called photons, and that photons impart their entire energy to electrons.
3) The document also discusses de Broglie's hypothesis that all matter exhibits wave-particle duality, and derives an expression for the de Broglie wavelength of matter particles.
B.tech sem i engineering physics u iv chapter 1-atomic physics
1. Classical physics describes large, everyday objects but fails to describe phenomena at the atomic scale. Quantum physics was developed in the early 20th century to address these shortcomings.
2. Quantum physics is counterintuitive, but it is the most successful physical theory ever developed. It underlies our understanding of atoms, molecules, and subatomic particles.
3. Quantum physics recognizes that waves and particles are less distinct than previously thought. Key insights include that light can behave as particles called photons, and particles can behave as waves.
Chapter 3 photoelectric effect
The document summarizes key concepts about the photoelectric effect from the chapter on photoelectricity. It discusses 5 main topics to be learned: how intensity and frequency of light affect photoelectrons, photoelectric current graphs, quantitative equations for work function and threshold frequency, the photon theory of light, and why wave theory fails to explain the photoelectric effect. It provides definitions and examples of photoelectric terms and experiments. The document contrasts predictions of wave and photon theories, and shows photon theory agrees with experimental results that kinetic energy increases linearly with frequency.
Photoelectric effect .pptx
1. The photoelectric effect occurs when light of sufficient frequency shines on a metal surface, causing electrons to be emitted.
2. Einstein explained the photoelectric effect using the photon model of light, where light consists of discrete packets of energy called photons.
3. The kinetic energy of emitted electrons depends on the frequency of light, not its intensity, supporting the photon model over classical wave theory.
Quantum chemistry-B SC III-SEM-VI
This document provides an overview of quantum mechanics. It begins by explaining that quantum mechanics describes the motion of subatomic particles and is needed to understand the properties of atoms and molecules. It then discusses some key developments in quantum mechanics, including Planck's quantum theory of radiation, Einstein's explanation of the photoelectric effect, de Broglie's hypothesis of matter waves, Heisenberg's uncertainty principle, and Schrodinger's wave equation. The document also compares classical and quantum mechanics and provides examples of quantum mechanical applications like atomic orbitals and black body radiation.
Photoelectric effect ppt
Einstein proposed that light is made up of discrete packets called photons. Each photon has an energy proportional to its frequency. Photons have no mass or charge and travel at the speed of light. The photoelectric effect occurs when photons of sufficient frequency eject electrons from metal surfaces. Experiments showed that the kinetic energy of ejected electrons depends on photon frequency, not intensity. Einstein explained this using a quantum model where photons transfer discrete units of energy. Photoelectric cells and light dependent resistors use this effect, finding applications in cameras, alarms, and other devices.
202004091956360894nkpandey_Photoelectric_Effet.pdf
The photoelectric effect occurs when electromagnetic radiation such as ultraviolet light ejects electrons from metal surfaces. Einstein explained this effect by proposing that light is quantized into discrete packets of energy called photons. When a photon with sufficient energy, determined by the metal's threshold frequency, strikes an electron, it transfers its full energy and can eject the electron. The maximum kinetic energy of ejected electrons depends only on the frequency of incident light, not its intensity, while the rate of electron ejection or photocurrent increases with intensity.
EP PPT.pptx
A toolbox (also called toolkit, tool chest or workbox) is a box to organize, carry, and protect the owner's tools. They could be used for trade, a hobby or DIY, and their contents vary with the craft. Engineering physics, or engineering science, refers to the study of the combined disciplines of physics, mathematics, chemistry, biology, and engineering, particularly computer, nuclear, electrical, electronic, aerospace, materials or mechanical engineering. Areas might include aerospace, biophysics, medical physics, renewable energy (photovoltaics, battery technology, fuel cells, ...), transportation, quantum information science, semiconductors, or materials development. Question: Is Engineering Physics hard? With both Engineering and Physics, the course is definitely challenging. It covers several aspects of a variety of different industries while most engineering courses cover only one industry.
Black body radiation.
PLAN'S THEORY
Stefan’s Law,
Wien’s displacement law
Bhor's Model and its limitations
PHOTO ELECTRIC EFFECT
COMPTON EFFECT
19_quantum [Autosaved].ppt
CONTENTS
INTRODUCTION
NEED FOR CYBER LAWS
CYBER LAWS IN INDIA
CYBER CRIMES
OFFENCES AND LAWS IN CYBER SPACE
CYBER LAWS AMENDMENTS
CONCLUSION
INTRODUCTION
What is Cyber Law?
Cyber Law is the lawgoverning cyber space.Cyber space is a very wideterm and includescomputers, networks,software, data storagedevices (such as hard disks,USB disks etc), theInternet, websites, emailsand even electronic devicessuch as cell phones, ATMmachines etc.
Cyber lawencompasses lawsrelating to
:
1. Cyber Crimes
2. Electronic and DigitalSignatures
3. Intellectual Property
4. Data Protection andPrivacy
NEED FOR CYBER LAWS
TACKLING CYBERCRIMES
INTELLECTUALPROPERTYRIGHTS ANDCOPYRIGHTSPROTECTION ACT
NEED FOR CYBER LAWS
1. Cyberspace is an
intangible
dimension that is impossible togovern and regulate usingconventional law.
2. Cyberspace has complete
disrespect for jurisdictionalboundaries
. A person in Indiacould break into a bank’selectronic vault hosted on acomputer in USA and transfermillions of Rupees to anotherbank in Switzerland, all withinminutes. All he would need is alaptop computer and a cellphone.
3. Cyberspace
handlesgigantic traffic volumesevery second
. Billions ofemails are crisscrossing theglobe even as we read this,millions of websites are beingaccessed every minute andbillions of dollars areelectronically transferredaround the world by banksevery day.
4. Cyberspace is
absolutelyopen to participation by all.
A ten year-old in Bhutan canhave a live chat session with aneight year-old in Bali withoutany regard for the distance orthe anonymity between them
ABOUT AUTHOR
Sumit Verma
Chitkara University
Undergraduate
PAPERS
1
FOLLOWERS
575
Follow
RELATED PAPERS
Important question answers Information Technology Act, 2000
Suvo Chatterjee
Download
More Options
IT ACT 2000 – PENALTIES, OFFENCES WITH CASE STUDIES From
aru mugam
Download
More Options
Information Technology
trinisha chakroborty
Download
More Options
OVERVIEW OF CYBER LAWS IN INDIA Index
aneesh tvm
Download
More Options
Critical analysis of proposed cyber Crime Bill 2015
Shahid Jamal T U B R A Z Y Cyber Lawyer
Download
More Options
Final Cyber Cri
Prashant Dabhade
Download
More Options
Cyber Laws in India
Vikas Khatkar
Download
More Options
Commentary on THE INFORMATION TECHNOLOGY ACT, 2000
Rohas Nagpal
Download
More Options
INTRODUCTION TO THE ACT 2. NEED AND OBJECTIVES 3 ROLE OF IT IN ECOMMERCE 4 CYBER CRIME 5 ELECTRONIC SIGNATURES 6 E-GOVERNANCE
keshav agarwal
Download
More Options
NON BAILABLE OFFENCES( Cyber Crimes) UNDER The IT Act, 2000 (Cyber Law)
Adv Prashant Mali, Ph.D.
Download
More Options
P a g e Fundamentals of Cyber Law Rohas Nagpal Asian School of Cyber Laws
vijay onlinesangli
Download
More Options
SEMINAR AND WORKSHOP ON DETECTION OF CYBER CRIME AND INVESTIGATION Presented by
chayapathi A R
Download
More Options
Cyber Crime Investigation and Trial Procedure in Bangladesh: Comparison with India
Thohedul Islam Talukdar
Down
Similar to light (1).pptx (20)
Subhadeep_BSPH101.pptx dsuyfgwf7ywidvweiufwetdfiuqefuhygedfiewgfi
Subhadeep_BSPH101.pptx dsuyfgwf7ywidvweiufwetdfiuqefuhygedfiewgfi
B.Tech sem I Engineering Physics U-IV Chapter 1-ATOMIC PHYSICS
B.Tech sem I Engineering Physics U-IV Chapter 1-ATOMIC PHYSICS
Modern_Physics,_Photoelectric_Effect_&_X_rays_BOUNCE_BACK_24_DEC (1).pdf
Modern_Physics,_Photoelectric_Effect_&_X_rays_BOUNCE_BACK_24_DEC (1).pdf
B.tech sem i engineering physics u iv chapter 1-atomic physics
B.tech sem i engineering physics u iv chapter 1-atomic physics
202004091956360894nkpandey_Photoelectric_Effet.pdf
202004091956360894nkpandey_Photoelectric_Effet.pdf
Recently uploaded
How to deliver Powerpoint Presentations.pptx
"How to make and deliver dynamic presentations by making it more interactive to captivate your audience attention"
RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
Physical pharmaceutics notes for B.pharm students
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...Nguyen Thanh Tu Collection
https://app.box.com/s/qhtvq32h4ybf9t49ku85x0n3xl4jhr15Gender and Mental Health - Counselling and Family Therapy Applications and In...
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
HYPERTENSION - SLIDE SHARE PRESENTATION.
IT WILL BE HELPFULL FOR THE NUSING STUDENTS
IT FOCUSED ON MEDICAL MANAGEMENT AND NURSING MANAGEMENT.
HIGHLIGHTS ON HEALTH EDUCATION.
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...Nguyen Thanh Tu Collection
https://app.box.com/s/tacvl9ekroe9hqupdnjruiypvm9rdaneLeveraging Generative AI to Drive Nonprofit Innovation
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"National Information Standards Organization (NISO)
This presentation was provided by Racquel Jemison, Ph.D., Christina MacLaughlin, Ph.D., and Paulomi Majumder. Ph.D., all of the American Chemical Society, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.Walmart Business+ and Spark Good for Nonprofits.pdf
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
مصحف القراءات العشر أعد أحرف الخلاف سمير بسيوني.pdf
مصحف أحرف الخلاف للقراء العشرةأعد أحرف الخلاف بالتلوين وصلا سمير بسيوني غفر الله له
How to Setup Warehouse & Location in Odoo 17 Inventory
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptx
Iván Bornacelly, Policy Analyst at the OECD Centre for Skills, OECD, presents at the webinar 'Tackling job market gaps with a skills-first approach' on 12 June 2024
Recently uploaded (20)
RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
REASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdf
REASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdf
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...
Gender and Mental Health - Counselling and Family Therapy Applications and In...
Gender and Mental Health - Counselling and Family Therapy Applications and In...
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...
B. Ed Syllabus for babasaheb ambedkar education university.pdf
B. Ed Syllabus for babasaheb ambedkar education university.pdf
Leveraging Generative AI to Drive Nonprofit Innovation
Leveraging Generative AI to Drive Nonprofit Innovation
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"
Walmart Business+ and Spark Good for Nonprofits.pdf
Walmart Business+ and Spark Good for Nonprofits.pdf
مصحف القراءات العشر أعد أحرف الخلاف سمير بسيوني.pdf
مصحف القراءات العشر أعد أحرف الخلاف سمير بسيوني.pdf
How to Setup Warehouse & Location in Odoo 17 Inventory
How to Setup Warehouse & Location in Odoo 17 Inventory
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptx
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptx
light (1).pptx
- 1. Photon ~ Quantum of Energy ~ Outline - Light as Waves - Light as Particles . Photoelectric Effect - photon energy . Compton Effect - photon momentum Acknowledgement: Some of slides are adopted from PHY106 Particle Physics Module at Syracuse University by Dr. Steve Blusk In physics, a quantum is the minimum unit of any physical entity involved in an interaction. The word comes from the Latin “quantus” for “how much.”
- 2. Light waves: Characterized by: Amplitude (A) Frequency (ν) Wavelength (λ) Maxwell Showed us that Energy of EM wave ~ A2 Light Waves EM FIELDS FOR LASER DRILLING EM FIELDS FOR WARMING EARTH Until about 1900, the classical wave theo ry of light described most observed phenom ena wavelength amplitude Image by Metaveld BV http://commons. wikimedia.org/wiki/File:Lasersnijden_ laserkop.jpg on Wikimedia Commons Image is in the public domain
- 3. Are Photons Particles or Waves ? Newton believed that light was particles: • what is ‘waving’ in an EM wave ? A wave is a vibration of some medium through which it propagates, e.g., water waves, waves propagating on a string Light Source Barrier Particles Produce Straight Shadows Image by fotostijnl http://www. flickr.com/photos/stijntje/20580 70484/ on flickr • light travels in straight lines ! Image in public domain Image is in the public do main
- 4. Waves Bend Into Shadow We described them as WAVES up till now air oil water Constructive Interference Incident light Barrier Young’s Double Slit Experiment Light Propagation Direction Destructive Interference Constructive Interference Coherent Sunlight From Single Slit Screen Image in the Public Domain Image by Pieter Kuiper http://commons. wikimedia.org/wiki/File:Compact-Disc-spectrum- Mercury.jpg on wikimedia commons
- 5. Interference is the defining characteristic of waves Thomas Young’s Double Slit Experiment But what happens when we reduce the intensity of incid ent light … everything shoul d just get dimmer … Right ? Screen Partition with two very small thin slits (shown here greatly enlarged) to let light through. ? ? Image is in the public domain
- 6. Photoelectric Effect When light is incident on certain metallic surfaces, electrons are emit ted from the surface – This is called the photoelectric effect – The emitted electrons are called photoelectrons The effect was first discovered by Hertz The successful explanation of the effect was given by Einstein in 1905 – Received Nobel Prize in 1921 for paper on electromagnetic radiation, of w hich the photoelectric effect was a part Classical Picture Quantum Picture EM wave Photons Electrons sh aken loose by an EM wa ve Electrons knoc ked loose by photons - - - - - -
- 7. Photoelectric Effect Schematic When light strikes E, photoelectrons are emitted Electrons collected at C and passing through the ammeter are a current in the circuit C is maintained at a positive potential by the power supply Light A V Variable Power Supply
- 8. No electrons were emitted until the frequency of the light exceeded a critical frequency, at which point electrons were emitted from the surface ! (Recall: small λ large ν) Vary wavelength, fixed amplitude What if we try this ? electrons emitted ? No Yes, with low KE Yes, with high KE Increase energy by increasing amplitude “Classical” Method electrons emitted ? No No No No Observation of the Photoelectric Effect … a Quantum Phenomenon
- 9. Consequences for Imaging We see that photons are detected with probability proportional to intensity PROBABILITY OF DETECTION OF EACH PHOTON PER UNIT AREA: Image by Rory Moynihan http ://www.flickr.com/photos/r tmoynihan/5613097441/ on f lickr
- 10. SOLAR SAIL at rest INCOMING PHOTONS 1000 W/m2 every second photons with momentum + (1000 J/m2)/c impact the sail SOLAR SAIL moves REFLECTED PHOTONS 1000 W/m2 every second photons with momentum - (1000 J/m2)/c leave the sail with momentu m + (2000 J/m2)/c … and gets that much more mo mentum every s econd … Pressure acting on the sail = (2000 J/m2) /c /second = 6.7 Newtons/km2 Photon Momentum - Moves Solar Sails Photon Momentum - Moves Solar Sails Image by D. Kassing http://en.wikipedia.org/wiki/File:SolarSail- DLR-ESA.jpg on Wikipedia Image in the Public Domain