In what year did J.J. Thomson find the first evidence for isotopes of a stable element?
1897
1906
1913
1920
Answer
J.J. Thomson found the first evidence for isotopes of a stable (non-radioactive) element in 1913. This discovery was part of his exploration into the composition of canal rays (positive ions) and furthered our understanding of atomic structure.
Unlocking the Secrets of the Atom: The J.J. Thomson Chronicles!