Doppler effect, red shift and stellar spectra

I think you need to be a bit careful talking about red shift and stars as well as most mark schemes will not credit a response where they discuss stars, I replaced the stars with galaxies therefore. Still thanks, nice activities.

Very good end of topic assessment worksheet, and open ended questions with some help and guidance. I though this was very good. However is it me or is this statement ". Some lines seem to appear at higher wavelengths (blue shifted) and some at lower wavelengths (red shifted)" wrong? Redshift = Longer wavelength??? Personally I'd drop mentioning blue shift as this confused a lot of the class, as we mainly want them to have proof that the universe is expanding. Clouding it with certain galaxies moving towards us, just adds an unwanted layer? Concentrate on driving home point about redshift, except with more able students? Overall a very good assessment worksheet that I'll modify for several other topics. Thanks.