He invented the Geiger counter.
The Geiger Counter was developed by Hans Geiger.
If you're talking about the experiment with the alpha particles, then it was Hans Gieger and Ernest Marsden.
thermometer
the electric generator
the geiger counter
yes!
Yes, in 1922.
The electric battery
21
him and his son helped invent the compound microscope by putting two lenses together warning they did not invent the microscope but did invent the compound microscope
Bonn, Germany.
he co invented the jet engine