Question

Becquerel’s experiment consisted of four steps. A. Get a sample of a uranium salt. B. Expose the salt to sunlight. C. Expose photographic plates to the salt.
D. Develop the plates.
A change in which step led to Becquerel’s discovery of radioactivity?

Answer 1

C =EXPOSE PHOTOGRAPHIC PLATE TO THE SALT

Answer 2

Becquerel’s discovery of radioactivity is obtained by exposing photographic plates to the salt.

Explanation:

The Becquerel discovery made for the radioactivity was achieved through the step C of the four steps mentioned in the question.

He initially rendered his experiment as a failure due to the reason of overcast in the Paris. But somehow he thought to still continue the development of his plates of photography. This decision led to the change in the step C as exposure of photographic plates to the salt, and led to the discovery of radioactivity.