$$ PHOTOELECTRIC EFFECT PhET LAB$$ PHOTOELECTRIC EFFECT PhET LABS electrons libe

Question

$$PHOTOELECTRIC EFFECT PhET LAB$$

PHOTOELECTRIC EFFECT PhET LABS electrons liberated from the surface? Try it out and describe and explain your results here. Part 3 What determines if electrons are liberated from the surface? 1. You have probably noticed in Parts 1 and 2 that under some condition, no electrons are liberated from the metal surface. Remember that it takes energy to remove electrons from the metal. Why can't all light cause electrons to leave the surface? 2. If you run simulation under a particular s of conditions and no electrons are being the emitted, what could you adjust to make electrons start coming out? Try this, and then describe and explain your results. 3. It turns out that it takes different amount of energy for electrons to be liberated from different metal surfaces. To investigate this, start with the light wavelength (low energy and slowly move the wavelength slider until you begin to see electrons move across the screen

Explanation / Answer

We know that FREQUENCY = SPEED OF LIGHT/WAVELENGTH

Now, there is certain requirement of frequency to be fulfilled by a particular light. If the frequency is not as required, no electron will be emitted. However, we can take a chance by increasing the intensity.

However, lights with frequency above threshold frequency will easily eject the electrons even if the intensity is low.

This threshold frequency is different for different material. It has been proved that quanta or a photon of light must have frequency greater than the atom's ionization energy for easy and instant ejection of electron.

As far as part (3) is concerend, as we start with higher wavelength means lower frequency, the electrons may not move or eject from the metal surface, you can try increasing the intensity but it may not have any effect. But as we go towards low wavelength means high frequency, the energy required to eject an electron from the metal surface decreases. However, we must note that not all the metal surfaces behave similar. Some may require extremely high frequency or some may need moderate frequency for photoelctric effect.

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.