Why did j. j. thomson reason that electrons must be a part of the atoms of all elements? (1 point) cathode rays are negatively charged particles. cathode rays can be deflected by magnets. an electron is 2000 times lighter than a hydrogen atom. charge-to-mass ratio of electrons was the same, regardless of the gas used.

D. charge-to-mass ratio of the electrons was the same, regardless of the gas used. 

any type of gas used for the experiment, emitted rays which contained electrons, whose charge-to-mass ratio remained the same. he made the statement that the  rays are made up of  electrons:   very small, negatively charged particles that are indeed fundamental parts of every atom.

It is the areas with lines. this may sound a little confusing, but i hope it !