Question

A metal that is used as an electron emitter is?

Answer 1

Electron emitter is also called an electron gun. Electron emitter which produces a narrow collimated electron beam which in turn possesses kinetic energy. Electron emitter is an electrical component and electron emitter is used in cathode ray tube, television sets, computer display, and oscilloscope and also used in the field emission display (FEDs).

Complete step-by-step solution:
Tungsten is a metal which is used as an electron emitter and the symbol used to represent tungsten is W. Atomic number of tungsten is 74 and it is a rare metal. Tungsten has a very high melting point of 3655k and a moderate work function.
For thermionic emission tungsten is the suitable metal and it starts emission at 2500k and boiling point of tungsten metal is 6203k.Tungsten metal has a density of $19.3gc{{m}^{-3}}$and the molar heat capacity of tungsten metal is $24.27J/(mol\cdot K)$.
Tungsten metal which belongs to group 6 in the periodic table and it is a d-block element. The thermal conductivity of tungsten metal is $174W/(m\cdot K)$

Note: Students Electron gun is classified based on the type of electric field generation, by emission, by focusing, or by the number of electrodes. Tungsten is used in heavy metal alloys and tungsten which is solid at room temperature .Tungsten metal which has excellent corrosion resistance and also has high tensile strength.