26.4 Photons

• Scientists faced a serious dilemma in the first three decades of the 20th century.

• If we accept this model, we must have both wave-like and particle-like behaviors.
• The dual nature of pho tons was tested in a dramatic way.

• The hypothesis that has both particle and wave properties was ported by Soviet physicists.

• A double-slit setup was used by Vavilov and Brumberg.
• They wanted to make it easier to detect individual photons by reducing the number of them that pass through the slits.
• They used extreme sensitivity to low intensities of light to detect.
• A person who is sitting in a dark room for extended periods of time develops increasing visual sensitivity to the extent that he or she can eventually see the individual photons hitting a screen that has been covered with a special material.

• There is a light source with variable intensity.

• Only two bright bands should appear.

• There should be many bright and dark bands.

• There should be many bright and dark bands.

• The flashes at low intensity indicate that the photons hit the screen.

• There are places where constructive wave interference occurs.

• Both wave-like and particle-like behaviors are exhibited by the photons.

• The results of the experiment were astounding-- they only reached screen locations where the waves from the two slits would not interfere with each other.
• It is as if each individual photon passes through both slits, interfering with itself, and then producing a flash only at a location on the screen where constructive interference occurs.

• The idea of a photon as a single quantum of radiation was constructed earlier in the chapter.
• It seems impossible that it could pass through both slits at the same time.
• The experiment supports this strange idea.

• The photoelectric effect is what we have seen.
• This suggests that the photon must have something in it.
• Because they travel at light speed, they must be treated with care.

• There are difficulties when applying this expression to a photon.
• If they are quanta of electromagnetic radiation, they would seem to be composed of electric and magnetic fields.
• The nu merator should be zero.

• We need an expression that doesn't have a square root factor.

• In the second equation, 22 is added to the first equation.
• This takes a lot of math.

• There is a new equation for the total energy of an object.

• In other words.

• What happens when Eq.

• The total energy of this expression is reasonable.
• We will talk about the object at rest and the experiment later in the chapter.

• The sun is 1030 km away.

• The Sun emits over 1045 photonss.

• There is an assumption that al photons have a Frequency of 1014 Hz.
• It will be different.

• X-rays will be used to test this expression.
• We need to know about X-rays.

• The story of X-rays is an example of how persistence and attention can lead to discoveries.
• The photoelectric effect was explained by the idea that free electrons reside inside metals.

• Physicists didn't know that metals con heats cathode in the 19th century.

• There was a potential difference across the electrodes.

• There are some ways to study the photoelectric effect.
• The difference was that the bat tery's negative terminal could be heated to high temperatures, instead of being exposed to light.

• When the tube was heated, a current appeared in the circuit and it glowed.
• The tube's interior was a vac uum, so they thought that the cathode must emit some kind of rays.

• The Cavendish Laboratory at Cambridge University was where J. J. Thomson was working.
• When the rays hit the metal target, it became negatively charged.
• Thomson found that the rays could be diverted by electric and magnetic fields as though they were negatively charged particles.
• Experiments by other scientists portended the latter hypothesis.
• The charge-to-mass ratio was not dependent on the choice of material.

• Thomson concluded that there was only one type of cathode ray.

• If we can explain the behavior of the cathode ray tubes, we can model a stream of charged particles.
• The tube is hot.
• The particles inside the cathode have a large amount of random motion and could knock each other out.
• The electric field between the anode and the cathode would cause them to accelerate.

• The chemists were trying to find out what electric currents were made of.
• The value of the smal est charge carried by these particles was determined through experiments.

• The mass of the electron is less than that of a hydrogen atom.

• The electron is a point tube.
• If you put the tube in on the electron and the Earth exerts the same force on it as it does on the electric, what happens?

The forces of the electric and magnetic are shown in the 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846

• The negatively charged elec speed can be determined by determining the charge-to-mass ratio.

• The trons follow a path.

• There should be a relationship between downward.

• Experiments with tubes led to the discovery of X-rays.

• When Roentgen was ready to leave the lab, he covered the cathode ray tube with cardboard and turned off the lights.
• The room was dark and the tube was covered in cardboard.
• The lights were turned back on by Roentgen.

• The screen was not bright.

• Most people would have exhaled a sigh of relief and left.

• The tube is completely covered.
• Roentgen could see a shadow on the screen when he placed his hand near it.

• The screen glowed as though the flesh of his hand was transparent, and only his bones stopped it.

• At the time he couldn't explain what the rays were, he called them X-rays.
• The first X-ray image of a human was made by Roentgen on December 22, 1895.
• X-rays are still called X-rays even though we know what they are.

• X-rays are unaffected by magnetic or electric fields.

• The X-rays don't cause the screen to charge.

• The photographic paper is affected by X-rays.

• After a single narrow slit, the X-rays produce a pattern of dark and bright bands on the screen.

• X-rays can be different colors.

• There are many materials that can be X-rayed.

• X-rays can be used to ionize gases.

• The X-rays had a wavelength of 10 to 11 m, which was much smaller than visible light.
• It is reasonable to think that X-rays are streams of high energy photons.

• The metal is very hot due to their high random motion.

• The electrons are hot when they escape the cathode.

• When an electron stops when it collides with the anode, it emits electromagnetic radiation.
• The radiation may be in the form of electron is ejected.

• The X-rays are emitted when there is an X-ray photon.
• The amount of energy produced by the electrons is estimated.

• We want to know if the electrons are enough to produce an X-ray photon.

• The potential difference between the electric field produced in a hospital and the one produced by a single X-ray tube is considered.
• Each part of the process is represented by electrons that stop abruptly a work-energy bar chart.
• The initial state shown below is when they collide with the anode and emit light.

• The process is sketched in three zero electric potential energy.

• The electron smashes into the anode.
• The X-ray photon has been emitted.

• The energy characteristic of vis ible light is less than this.

• The generalized work-energy principle is higher than visible light frequencies and can be applied using the first and second state.

• The constant is 10-34 J #s.

• The result of our calculation shows that an elec tron can produce an X-ray photon when it stops.

• Each photon must have a specific amount of momentum.
• We thought LF moved away at angle U.

• We need to describe the process.

• The stationary electron has zero initial momentum.

• The energy of the system should be constant.
• The system has no electric potential energy because the pho ton is neutral.
• The internal energy of the sys tem is zero because the photon and electron have no internal structure.
• We need to keep track of the energy of the electron and the photon.

• The equation can be combined with the two equa tions into a single relationship that describes the collision between the X-ray photon and the electron.
• It is complicated because of the high speeds involved.

• The wavelength of an X-ray photon after the col ision should always be greater than or equal to the wavelength before the collision if the hypothesis about X-rays behaving like particles is correct.
• The right side of the book is the reason.
• The magnitude of the photon's momentum can change.
• The finding is reasonable because of the transfer of the photon's momentum to the electron.

• Arthur Compton conducted an experiment in 1922 to find out if the photon's wavelength actually changes.
• He shot a beam of X rays.
• The binding energy between the electrons and the carbon atoms is 1000 times greater than the X-ray photons.
• The electrons can be approximated as isolated and not interacting with the carbon atoms.

• The photons had different wavelength than the incident.
• The change in the photon wavelength as a function of its scattering angle was consistent.
• With greater confidence, we can assert this idea.

• The ideas about scattering from charged particles can now be summarized.

• The effect that carries his name was described by the winner of the 1927 Nobel Prize.

• Each photon has enough energy to knock electrons out of atoms or to break bonds that hold atoms together in molecule, so they are cal ed ionizing radiation.
• Ionizing radiation can damage genes and increase the risk of cancer.
• The chance of serious harm from UV and X-ray exposure is reduced by the body's potent DNA repair mechanisms.
• People who work around ionizing radiation have to take precautions.

• If the body absorbs a total of 1 then the chest X-ray will be 10-3 J.

• Three times as long the number of photons will be.

• Cosmic rays coming from supernovae and other objects in the universe can be seen in the food you eat.
• You absorb about 10-3 J of this radiation per kilogram of body mass.
• Estimate the number of seconds that the ionizing and the strontium-90 particles are absorbed each second.

• Assume for nisms to take care of radiation exposure.

• We can determine the number absorbed each time we are exposed to radiation.

• The X-ray photons have particle-like behavior.
• X-rays can exhibit wave-like behavior if they can be made to interact with objects that are similar to the wavelength of the X-rays.
• The order of magnitude is the same as the wavelength of X-ray photons.
• The pattern of visible light and/or UV radiation is very similar to that of the crystal lattice.
• The electrons move to the collector.

• The structure of genes can be determined using X-ray scat tering.

• A key role in determining the structure of DNA was played by British biophysicist Rosalind Franklin.

• The electrons go from the emitter to the collector in photocells and solar cells.

• There are many applications of the photoelectric effect.

• An electric current detector is caused by a photoelectric smoke electrons being ejected and absorbed by the col ector.

• The magnitude of the current is a measure of the visible light.

• Solar cells, such as the rooftop panels used to generate electric current, are triggered when the pho tocurrent reaches a certain level.

• The No smoke Semiconductor technology we discussed in the earlier chapter is used to make solar cells.

• Semiconductors act as conductors under some conditions.

• Silicon is used in electronics.

• Each electron is shared between them.
• A light reaching electrons is an electric insulator.
• When the photocell light shines on it, some of the electrons gain enough strength to make an alarm sound.

• Smoke holes can be filled by other bound electrons that aren't as energetic as Smoke scatters light can still move among the still-bound elec trons.
• If the Silicon is placed in an electric field, both free electrons and holes can potentially contribute to a current.

• The alarm process uses light and Scattered light to increase the energy of the Silicon and allow some of it's electrons to be free.
• The be freed depends on the light's frequencies.

• Enhancing the purity of Silicon is one way to turn it into a conductor.
• The two types of impurities are electron donors and electron acceptors.

• Doping of a substance.

• Charge transfer across the junction is not caused by light p- and n-type Semiconductors.

• A free electron is produced.

• For an electron acceptor, the opposite is true.
• Boron has holes because it absorbs the Sun's three electrons.
• Extra holes can be created by the separation of the electric field bond with the adjacent Silicon atoms.

• The holes act as free positively charged particles without the presence of light.

• The crystals are completely composed of neutral atoms.

• An electric field is produced by this charge separation.

• If we shine light on the p-n junction, both halves cause a hole to move left and the junction will absorb energy from the left side.

• The freed electrons and holes are separated by an electric field created by the p-n junction.
• If we connect a lightbulb to the two ends of the p-n junction, we will see a current in the circuit and the bulb will light.
• The energy of light is converted into electricity.

• The electron has zero energy when it leaves the metal if the photon energy is greater than f.

• The maximum speed electron can't reach the anode.

• If you triple the temperature of a black body, the 10.

• The wavelength frequency is the temperature of a black body.

• You can choose al of the photoelectric 11.

How do we know that there is a particle-like model of light?

• The intensity of light is proportional to the photon model of light.

• The photon model of light and rent are different.

• The Sun emits X-rays.
• The intensity of light is what determines why we are.

• The photoelectric effect and the Comp 7 are very different.

• The photoelectric effect has a photon with momentum.

• The work function of cesium is 2.1 eV.
• Someone could be sium.

• Determine how much diation is emitted by each surface.

• A blue tion could be a solution to the problem of where the most energy comes from.

• The stars range in color from red to blue.
• In an old-fashioned camera, the film color indicates the frequencies at which the star is exposed when light strikes it, estimating chemical reaction.
• The surface temperature of red, yel ow, white, and blue stars is not caused by a particular type of film.

• The lightbulb's surface area should be estimated.

• The surface temperature of the filament when it is plugged into an outlet of 120 V is 3000 K and the power 18.
• The electric energy/s that the bulb consumes is the electric energy/s that the carbon monoxide molecule rating of the bulb produces.
• Incandescent lightbulbs use about 10% of the electric energy that they consume, so they use the same visible Frequency of CO vibration as the Frequency light.

• Suppose the bond in a molecule is broken by a single photon from 1.0 cm2 of energy.
• Determine the fre person's skin if a typical emitted photon has a wavelength of quiescent and a region of 10,000 nm.

• The photon's wavelength is 1240 nm.
• The ratio tech compares the average power of the surface of Earth to determine the wavelength of a photon.

• Exposure to the entire surface of a warm object in a tanning bed.
• It can do a lot of damage if wavelength 300 nm is used.
• The average temperature of Earth's surface is 15 C.

• Determine the number of 650-nm photons that have the same amount of energy as an electron.

• Draw a picture of a phototube and electric circuit body tissues.
• To study the photoelectric effect, you have to build a number.
• If you want to understand the purpose of each part, you need to label all of the 10.8@mm photons and the average power dur of the pulse parts.

• Write a problem for which the equa is 20 times per second for the unknown quantity in wavelength pulse of variable energy.
• It is possible to determine the number of photons in tion.

• About 1400 W>m2 is the intensity of light reaching Earth.
• Determine the number of particles.
• Each second, an incident reaches a 1.0@m2 area.

• Determine the energy in 28.
• Roughly 10% of the power of a 100 watt in crease of the electron, in units of electron volts, when the pho candescent lightbulb is emitted as light, is scattered from it.

• An electron hit by an X-ray photon of energy is equal to 104 eV.
• If the photon leaves the site of the collision, how will the answer change?

• To see a 0.20 J object.
• The light wavelength is 694.
• The minimum light pulse to be determined.

• A powerful laser can ond in order to see an object.
• The wavelength of the light and the lift and support glass spheres that are 20.0 * 10 m in diam radius are assumed.

• Ex eye can detect one photon of light of wavelength and how they work together to produce cathode rays.

• Each 31 would be the number of such photons that enter the eye.

• They are very efficient at converting.

• 33 are most living organisms.
• The fireflies use adenosine triphosphate as an energy mol ence.
• A firefly would crash into the X-ray tube if it was given a number of ATP molecules.

• The laser is moving toward the center of the screen.
• The light shines on the sail of a tiny 0.10-g cart that expression for the strength of the field so the electron hits the can coast on a horizontal frictionless track.

• The light is total.

• The light is a total field.
• The absorbed by the sail must be determined.

• There are comets.
• A person absorbs jects that move around the Sun while being X-rayed.
• The number of comet's head is determined by the amount of X-ray photons absorbed during the exam.

• When the comet is close to the sun, there are gases and dust.
• Independent absorbs X-ray radiation.
• The tail always points to a positive charged ion in the direction of the comet.

• Roughly 150 million km from Earth is the Sun.

• The original experiment involved scattering.

• Canis Major is the second-brightest star in the north ton when it collides with an electron or with a carbon ern sky.
• Its surface temperature is an atom and it travels at a 90 angle.

• The minimum number of plants that capture and store energy from the Sun should be estimated.
• Use the assumptions you used in mak to build complex molecules.
• The process begins.

• The reverse reaction releases a lot of energy.

• Determine the ratio of the energy released from one antenna to another until it reaches an "acceptor" molecule.
• The energy absorbed by the acceptor is passed to an electron transport chain, where it is captured and stored.

• The electron transport chain, dium surface with a work function of 2.2 eV, is made of waves.

• The light is reflected from a mirror.
• Determine the force that the light exerts on the mirror.

• Suppose one of the antenna molecules absorbs a photon.

• 1400 J>s # m2 is the photon and tion intensity of a molecule like this.
• The original energy state can be determined in about 10-8 s.

• The radiation on Earth is linked to the antenna molecule in the photosynthetic units.

• A photon is absorbed by one antenna.
• If we wanted to support molecule, we could levitate the person on a beam of light.

• The person's neighbors are more or less random.

• An electron is located in an open region of space port chain.
• The energy is struck by a photon of light at several places along this pathway.

• The photographs were taken with a regular camera and an infra.

What is the number of antenna molecules that can be absorbed by a black plastic bag?

• The photoelectric transfer of an electron to the electron transport chain can be accomplished if the neighboring antenna molecules are separated by 10 m.

• The antenna molecule that absorbed the photon is the source of the high-energy electron that transfers into an electron trans port chain.

• The man's glasses appear clear with the regular camera photo, which comes from the acceptor molecule that is excited by and black with the IR camera photo.

• A person's body can't be that way.

• The law gives the peak wavelength of the radia face.

• A and b and c radiation are included.