# 3 Quantum phenomena

This chapter covers the quantum phenomena of the photoelectric effect, excitation, fluorescence and line spectra. What is most important is to learn the ideas of photoelectric effect so you can construct a wordy answer to a 6-7 mark written question. Also make sure you know your Joules from your eV’s. Finally there are a lot of computer models to look at which help you visualise this topic make sure you spend the time looking through them

03 Quantum Phenomena Part A

03 Quantum Phenomena Part B

03-QM-Student-Booklet

Textbook-Extract

spectra

AS Physics Unit 3 Exam Questions

## Planck's Constant - Experiment to Estimate the Value of Planck's Constant

In this video a range of seven LEDs are used to investigate the relationship between photon energy and frequency so that a value for Planck's constant can be estimated.

There is ...
a worksheet that accompanies this experiment so you can attempt the analysis yourself.
Get it here: https://www.tes.com/teaching-resource/planck-s-constant-experiment-worksheet-12336895

In the follow up video (https://youtu.be/etsxej_nTGI) I analyse the results and calculate the value of Planck's constant yielded by the data. The spreadsheet used for analysis is available here: https://www.tes.com/teaching-resource/estimate-planck-s-constant-analysis-spreadsheet-12340515

* Heads up: the value of Planck's constant obtained in this experiment is an estimate and as you will find my value is very different to the data book value. It's quite bad on one level, but on another it may be useful for evaluation! *

Experiments about quantum concepts, like this one, are mandatory practicals for many physics specifications. So this is good practice for OCR physics A, AQA A-Level physics, Edexcel A-Level physics, CPAC, PAG, practical endorsement.

Relevant concepts: Planck's constant, quantum physics, LEDs, photons, electrons and potential difference.