Early Photoelectric Light Detectors Were Based on Cesium

question 34

Multiple Choice

Early photoelectric light detectors were based on cesium. Cesium metal has a work function of 3.43 *10^-19 J. What is the velocity of the photoelectrons ejected from a cesium surface when exposed to blue light at 400 nm?

• A) 2.90 * 10⁸ m/s
• B) 2.90 *10⁵ m/s
• C) 5.81 * 10² m/s
• D) 5.81 * 10⁸ m/s
• E) 5.81 *10⁵ m/s

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