Use the following photoelectric graph to answer the question: Photoelectric Effect for a Photomissive Metal Kinetic Energy (ev) Ń÷0 ⇒ NW A -2 Frequency (E14 Hz) 10 11 What is the work function of the experimental photo-missive material?
Particle Theory of Light
The particle theory of light was the proposal made by Newton in 1704 in his treatise Opticks. This is the most basic light theory, in which light is thought to be made up of microscopic particles known as "corpuscles" and that's why this particle theory of light is also named as Corpuscular theory of light.
Stopping Potential
In an experiment conducted by Heinrich Hertz, an apparatus was made where the incident light was made to fall on the metallic plate, it was discovered that metals emit electrons. The surface electrons are bound to metals with a minimum amount of energy and some of the incident photos enter the surface, they undergo collision with the atoms of the metal, they get absorbed and emit energy to an election, making it photoelectron, where the collision between the photons and electrons ejects the electrons out of the metal and with a negatively charged electron, causes photocurrent and when this current passes it creates an electric field where there is a potential difference at the output due to the anode and cathode of the electrode of the apparatus. This study involves the theory of Quantum physics and electromagnetism involving electromagnetic radiation and electromagnetic wave theory.
Quantization of Charges
An electron is a negatively charged subatomic particle either attached to an an atom or sticks to the nucleus of the atom. Electrons exert the negative charge that tries to balance the positive charge of the nucleus.
![**Photoelectric Effect for a Photomissive Metal**
**Graph Explanation:**
The provided graph illustrates the relationship between Kinetic Energy (in electron volts, eV) and Frequency (in Hertz, Hz) for a photomissive metal. Here is a detailed breakdown of the graph:
1. **X-Axis (Horizontal Axis):** This axis represents the frequency of incident light measured in petahertz (E14 Hz, where 1 E14 Hz = 10^14 Hz). The frequency values range from 0 to around 11 x 10^14 Hz.
2. **Y-Axis (Vertical Axis):** This axis represents the kinetic energy of the emitted electrons measured in electron volts (eV). The kinetic energy values range from -2 eV to 4 eV.
3. **Data Points and Line:** A series of blue data points are plotted on the graph, indicating the observed kinetic energy at different frequencies. A positive linear relationship between frequency and kinetic energy is evident, as illustrated by the best-fit line passing through the points.
**Question:**
What is the work function of the experimental photo-missive material?
**Understanding the Work Function:**
In the photoelectric effect, the work function (φ) is the minimum energy needed to eject an electron from the surface of the material. The kinetic energy (K.E.) of the emitted electrons is given by the equation:
\[ K.E. = h \nu - \phi \]
where:
- \( K.E. \) is the kinetic energy of the emitted electrons,
- \( h \) is Planck's constant (\( 6.626 \times 10^{-34} \) J·s),
- \( \nu \) is the frequency of the incident light,
- \( \phi \) is the work function of the material.
**Finding the Work Function:**
The intercept of the line on the kinetic energy (eV) axis (where the frequency is zero) is the negative of the work function. Observing the graph, the intercept appears to be about -2 eV (where the line crosses the Y-axis). Hence, the work function (φ) of the photo-missive material can be estimated as:
\[ \phi \approx 2 \text{ eV} \]
Thus, the work function of the experimental photo-missive material is approximately 2 eV.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F749cbf17-77bf-45bf-b7c3-9b7458118f86%2Fbd7d7aa2-be54-4bb3-9f76-d15e72a468f6%2Fkzg79ro_processed.png&w=3840&q=75)
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