Your teacher will place an object such as a paperclip, coin, metal washer, or a door key between photographic film and a radioactive source such as a watch.

They will be left undisturbed for several days, then the film will be developed to see what kind of picture was produced.

You might be interested in researching the work of Wilhelm Roentgen (1845-1923), a German physicist who placed his hand between a beam of electricity and photographic paper and found that the rays from the electricity produced a picture of the bones in his hand. The strength of the rays in X-Ray pictures is measured in "Roentgens."