Multiple choice

Who discovered canal rays?

  1. J. J. Thomson

  2. Goldstein

  3. William Crookes

  4. Chadwick

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

An anode ray (also positive ray or canal ray) is a beam of positive ions that is created by certain types of gas discharge tubes. They were first observed in Crookes tubes during experiments by the German scientist Eugen Goldstein, in 1886.