Question

What important result did Becquerel observe when he placed the uranium salt crystals and unexposed photographic film in a drawer?
-The crystals phosphoresced within the drawer and exposed the film.
-The crystals did not phosphoresce within the drawer but did expose the film.
-The crystals phosphoresced within the drawer but did not expose the film.
-The crystals did not phosphoresce within the drawer and did not expose the film.

Answer 1

The correct answer is "The crystals did not phosphoresce within the drawer but did expose the film."

Becquerel  is credited to have discovered radioactivity. Becquerel was studying the properties of x-ray using naturally fluorescent minerals. Uranium shows radioactive decay. It is the high energy invisible radiation from uranium that exposed the photographic film.

Answer 2

B) The crystals did not phosphoresce within the drawer but did expose the film