---
title: "A student investigates the photoelectric effect on a clean plate of calcium metal placed in an evacuated chamber. The threshold frequency (\\(\\nu_0\\)) required to eject an electron from the surface of the calcium metal is determined to be \\(7.0 \\times 10^{14} \\text{ s}^{-1}\\). The student shines four different monochromatic light sources, one at a time, onto the calcium plate. The properties of each light source are shown in the table below.  | Light Source | Wavelength (\\(\\text{nm}\\)) | Beam Intensity (\\(\\text{W}\\)) | | :— | :— | :— | | 1 | \\(300\\) | \\(0.05\\) | | 2 | \\(400\\) | \\(0.10\\) | | 3 | \\(600\\) | \\(1.50\\) | | 4 | \\(750\\) | \\(3.00\\) |  Which of the following correctly identifies all the light source(s) capable of ejecting photoelectrons from the calcium metal, and provides the correct justification?"
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url: "https://nerd-notes.com/ubq/123704/"
date_modified: "2026-09-28T12:02:03+00:00"
---

# A student investigates the photoelectric effect on a clean plate of calcium metal placed in an evacuated chamber. The threshold frequency (\(\nu_0\)) required to eject an electron from the surface of the calcium metal is determined to be \(7.0 \times 10^{14} \text{ s}^{-1}\). The student shines four different monochromatic light sources, one at a time, onto the calcium plate. The properties of each light source are shown in the table below.

| Light Source | Wavelength (\(\text{nm}\)) | Beam Intensity (\(\text{W}\)) |
| :— | :— | :— |
| 1 | \(300\) | \(0.05\) |
| 2 | \(400\) | \(0.10\) |
| 3 | \(600\) | \(1.50\) |
| 4 | \(750\) | \(3.00\) |

Which of the following correctly identifies all the light source(s) capable of ejecting photoelectrons from the calcium metal, and provides the correct justification?

A student investigates the photoelectric effect on a clean plate of calcium metal placed in an evacuated chamber. The threshold frequency (\(\nu_0\)) required to eject an electron from the surface of the calcium metal is determined to be \(7.0 \times 10^{14} \text{ s}^{-1}\). The student shines four different monochromatic light sources, one at a time, onto the calcium plate. The properties of each light source are shown in the table below.

| Light Source | Wavelength (\(\text{nm}\)) | Beam Intensity (\(\text{W}\)) |
| :--- | :--- | :--- |
| 1 | \(300\) | \(0.05\) |
| 2 | \(400\) | \(0.10\) |
| 3 | \(600\) | \(1.50\) |
| 4 | \(750\) | \(3.00\) |

Which of the following correctly identifies all the light source(s) capable of ejecting photoelectrons from the calcium metal, and provides the correct justification?

- **A.** Sources 1 and 2 only, because the frequency of the photons in both beams exceeds the threshold frequency \(\nu_0\).
- **B.** Sources 3 and 4 only, because their longer wavelengths provide photons with greater energy than the threshold required.
- **C.** Sources 3 and 4 only, because their higher beam intensities deliver sufficient total energy per second to overcome the threshold.
- **D.** Source 1 only, because it is the only beam with photons of high enough energy, while the frequency of Source 2 is below \(\nu_0\).

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123704/*