1. Bring up the internet and go to the following site: http://phet.colorado.edu/index.php
2. Look for "Run our Simulations", click "On Line", then "Light and Radiation" (in the left hand column), then "Photoelectric Effect", then "Run Now".
3. Keep the battery voltage at 0. Turn light intensity up to 100%. You will be testing Sodium first (metals are in the upper right hand box).
4. Adjust wavelength to a value which just allows electrons to leave the surface at slowest possible speed.
5. Calculate W in electrons volts using the following values and formulas:
c = ln, where c = 2.998E17 nm/sec, l is in nm and n is in s-1
h = 6.626E-34 J×s
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1 electron volt = 1.60217646 × 10-19 joules hn = Ek + W
***remember—Ek is set at zero
6. Calculate work function (in eV) for all other metals, including the mystery metal.
7. Look up work function values on the internet. Identify the mystery metal, and check the values obtained for the other metals.