Question

According to Becquerel, what created the image on photographic film when it was placed in a drawer with uranium salt crystals?

The crystals emitted something that affected the film the same way light did.
The film caused a chemical change in the crystals.
The film exposed spontaneously, even when it was not exposed to light.
The uranium spontaneously emitted radioactive particles that exposed the film.

Answer 1

the second choice

"the film caused a chemical change in the crystals"

Answer 2

Answer;

The crystals emitted something that affected the film the same way light did.

Explanation;

• Becquerel discovered the spontaneous emission of radiation from an element which he called radioactivity.
• He placed uranium salts on top of an unexposed photographic plate which was wrapped in a desk drawer and when the plate was developed, there was an intense silhouette on the film.
• He discovered that a piece of mineral which contained uranium could produce it's image on a photographic plate in the absence of light.