Does anybody know an activity I can give to my class in which deals with something Niels Bohr did?

Question

It has to be a lab that my class can do in groups.

He discovered that the number of electrons in the outer shell determines the chemical components.

Answer 1

Something involving atomic spectra. For example see
http://www.fas.harvard.edu/~scdiroff/lds/QuantumRelativity/StreetLampSpectra/StreetLampSpectra.html

Answer 2

It depends on the what grade you teach. You could have them build an atom out of items they find in the school or home. You could also have them find the far reaching implications of his ideas in the growth of physics and the world around us. That's a hard question!