Concept explainers
The description of the
Answer to Problem 1CQ
Photoelectric effect is the phenomenon in which the electrons are ejected from metals when light of certain frequency is incident on them. Photon model of light explained the experimental results of the effect using the quantum nature of light.
Explanation of Solution
Photoelectric effect is the phenomenon in which the electrons are ejected from the surface of a metal when
The second characteristic that could not be explained by classical theory was that maximum kinetic energy of the electrons depends on the wavelength of the incident radiation. This can be explained as shorter wavelength radiation has higher energy and this will provide more kinetic energy to the ejected electrons. The third characteristic is that photoelectric effect will not occur below a threshold frequency of the incident radiation. This can be understood as certain minimum amount of energy is required to free the electrons from the material to which they are bound. The final characteristic that puzzled the nineteenth century scientists was that the electrons are emitted virtually instantaneously after turning on a photon source. This is explained as each individual electron carries enough energy to cause the photoelectron to be emitted. Since only a single photon is required to eject an electron, the process happens instantaneously.
Conclusion:
Thus, the photoelectric effect is the phenomenon in which the electrons are ejected from metals when light of certain frequency is incident on them. Photon model of light explained the experimental results of the effect using the quantum nature of light.
Want to see more full solutions like this?
Chapter 27 Solutions
Physics
- What is meant by photo electricity? Describe the main features of photoelectric emission. Give an expression for the kinetic energy of the photoelectrons emitted from a surface, explaining what is meant by workfunction, the threshold frequency (or cut-offfrequency) and Planck's constant.arrow_forward1. What is the wavelength of a radio photon from an AM radio station that broadcasts at 1470 kilohertz? Express your answer to three significant figures and include the appropriate units. 2. What is the energy of a radio photon from the same station? Express your answer to three significant figures and include the appropriate units. For question 1 I am not sure how to solve it because the frequency is in kilohertz and I don't know how to convert it into something that I can use. For the speed of light in this question, would it be best to use 3 x 10^8 m/s or 3 x 10^5 km/s? For question 2 I have the formula to use, I'm just uncertain of how to use it.arrow_forwardState two properties of photons. For a monochromatic radiation incident on a photosensitive surface, why do all photoelectrons not come out with the same energy? Give reason for your answer.arrow_forward
- Answer this as soon and quickly as possible. Ive read the honor code and it states that their can be up to three sub-questions on each single questions. So please answer all the questions provided, thank you 1.What wavelength corresponds to light with a frequency of 3.87 x 1014 Hz? Please answer with the correct number of significant figures. Answer is in units of nm. Answer in decimal form. 2.What is the wavelength of a photon with an energy of 6.649 x 10-19 J? Please answer with the correct number of significant figures. Answer is in units of nm. Answer in decimal form.arrow_forwardExplain the physical processes described by the Einstein's photoelectric equation hv = 1/2mv2+ hv0 and state the significance of each term. Describe briefly how the values of h and vo can be determined.arrow_forwardWhat is the photoelectric effect? Write the important properties obtained as a result of experimental investigations on the photoelectric effect.?arrow_forward
- The photoelectric effect provided evidence that supported the early suggestion by Max Planck that electromagnetic waves exist as discrete packets of energy. a. Describe the energy transformations that occur during the photoelectric effect. b. If the incident light was not causing the emission of any electrons from the target metal, how could the light be changed to start causing emission of electrons? Explain your answer. c. Rather than changing the light source, explain why changing the target metal from part (c) may allow for the detection of emitted electrons.arrow_forwardLearning Goal: To understand the Bohr model of the hydrogen atom. In 1913 Niels Bohr formulated a method of calculating the different energy levels of the hydrogen atom. He did this by combining both classical and quantum ideas. In this problem, we go through the steps needed to understand the Bohr model of the atom. Part A Consider an electron with charge -e and mass m orbiting in a circle around a hydrogen nucleus (a single proton) with charge +e. In the classical model, the electron orbits around the nucleus, being held in orbit by the electromagnetic interaction between itself and the protons in the nucleus, much like planets orbit around the sun, being held in orbit by their gravitational interaction. When the electron is in a circular orbit, it must meet the condition for circular motion: The magnitude of the net force toward the center, F, is equal to mv²/r. Given these two pieces of information, deduce the velocity of the electron as it orbits around the nucleus. Express your…arrow_forwardLearning Goal: To understand the Bohr model of the hydrogen atom. In 1913 Niels Bohr formulated a method of calculating the different energy levels of the hydrogen atom. He did this by combining both classical and quantum ideas. In this problem, we go through the steps needed to understand the Bohr model of the atom. Part A Consider an electron with charge -e and mass m orbiting in a circle around a hydrogen nucleus (a single proton) with charge +e. In the classical model, the electron orbits around the nucleus, being held in orbit by the electromagnetic interaction between itself and the protons in the nucleus, much like planets orbit around the sun, being held in orbit by their gravitational interaction. When the electron is in a circular orbit, it must meet the condition for circular motion: The magnitude of the net force toward the center, F, is equal to mv²/r. Given these two pieces of information, deduce the velocity v of the electron as it orbits around the nucleus. Express your…arrow_forward
- How does Photon work in medicine? List 6 uses of LASER. What are fiber optics? How is this used in medicine? Aside from medicine, where else are fiber optics used? Where are the following optics used? a. Side Emitting Fiber Optics b. Tip Illuminated Fiber Optics c. Fiber Optic Light Pipes How does light travel? How does a prism split white light into a spectrum? How can we produce Magenta, cyan, and yellow? How does a pinhole camera work?arrow_forwardAn idealized radiating object does not reflect or scatter any radiation but instead absorbs all of the electromagnetic energy that falls on it. Can you explain why astronomers call such an object a blackbody? Keep in mind that even stars, which shine brightly in a variety of colors, are considered blackbodies. Explain why.arrow_forwardThe dark-adapted eye can supposedly detect one photon of light of wavelength 500 nm. Suppose that 100 such photons enter the eye each second. Part A Estimate the intensity of the light. Assume that the diameter of the eye's pupil is 0.50 cm. Express your answer in watts per square meter. Templates Symbols undo redo Teset keyboard shortcuts help I= W/m² ܬܘܝܐarrow_forward