In a cathode ray tube, the number of electrons that reach the fluorescent screen is controlled by the
a. deflecting plate.
b. anode.
c. grid.
d. cathode.

Grid 

The cathode serves as the positive terminal and the anode as the negative terminal. The flow of electrons is from the cathode to the anode.The relationship between a cathode and an anode involves electrons. An example of this is reaction that takes place in an electrolytic cell. It has a cathode compartment, an anode compartment and a salt bridge that divides the compartment. The movement of electrons is from the cathode to the anode. 

Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. and thus finally, if we have the 32s2− ion, there are 18 electrons, 16 protons, and 16 neutrons.