A stream of negatively charged particles is called:

alpha radiation

gamma radiation

a cathode ray

an X-ray

a cathode ray, look up JJ thomsons experiment

Alpha radiation is a stream of Helium nuclei.

An "alpha particle" is a bundle of 2 protons and 2 neutrons,

and each proton has a positive charge.

Gamma radiation and X-rays are both electromagnetic

waves, just like radio or light. They have no charge.

The stream of negatively charged particles is the cathode ray ...

a stream of electrons.