When Geiger and Marsden carried out the gold foil experiment in 1909, a lot was already known about alpha particles. Although...

Teaching Guidance 14-16

Students will have seen signs of electrons and positive ions (perhaps carrying a current through ionized neon or helium). On...

Teaching Guidance 14-16

Students will know that electrons carry energy and momentum when they are moving. Yet these moving electrons seem to be guided...

Teaching Guidance 14-16

As students start experiments on ionisation, they will have a fairly basic model of atoms and molecules as portrayed by the...

Teaching Guidance 14-16

No sooner do students see that light has a wave property (and have measured its wavelength) then this story is upset with...

Teaching Guidance 14-16

The Bohr planetary model of the atom is often what sticks in students’ minds. It provides a neat and familiar picture of...

Teaching Guidance 14-16

Hans Geiger was one of Rutherford’s students at Manchester University. He had been trying to make a workable detector to count...

Teaching Guidance 14-16