Rutherford’s scattering of alpha particles

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In the last part of the Higher course, we looked at the structure of the atom. Rutherford scattering of alpha particles fired at a very thin sheet of gold foil provided the evidence to develop our understanding of the atom from a “plum pudding” model to a “nuclear” atom – where most of the matter and mass are concentrated in the centre, or nucleus, of the atom.

There is a really good youtube video about Rutherford & alpha particle scattering –  watch the first 5 minutes only, it goes on to another topic after that. You can also follow the link below (the download link at end of post) to watch an animation of the alpha particle scattering experiment and follow how the results changed our view of the atom.

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Higher Unit 2 resit revision

If you are resitting the unit 2 NAB next Wednesday (29th April), you might want to look at the following revision sites:

XPhysics unit 2 revision

TPD, EMF and internal resistance 

Unit 2 summary (Powerpoint)

Whole course summary notes (pdf)

St. Kentigern’s Academy Notes:  unit 2.1,  unit 2.2,  unit 2.3,  unit 2.4,  revision questions,  answers to revision questions

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Photoelectric effect animation

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I found an useful simulation of the photoelectric effect here.  You can change the metal under investigation (we used Zinc in class).  You can also vary the wavelength and irradiance of the light.   Notice that below the theshold frequency you can’t get  any photoelectrons, even if you set the light to its brightest setting.

photoelectric effect

We looked at the photoelectric effect this week.  I’ve been looking for some video demonstrations but there are very few explanations that I would be happy to recommend.  The animation I used in class is available here.  I also found a nice demonstration on youtube (see below) that uses a different type of electroscope to indicate the presence of charge.

httpv://www.youtube.com/watch?v=RR4T1IlM2Jw

This video is also attached as a podcast.