Doubt regarding X- rays

[bananakicker456]

Hello everyone. My question is that can an electron if incident (on say, a metal ) with enough energy knockout another electron (of the metal atom)?. I know that atomic excitation can occur causing atomic electron to jump to higher energy level (bohr s model), but staright up knockout and then later form x rays? if yes, then is there a formula to derive the minimum amout of energy needed to do it, and is my claim even correct?

 

[Baluncore]

Welcome to PF.

My question is that can an electron if incident (on say, a metal ) with enough energy knockout another electron (of the metal atom)?.

Easily, when an electron hits a target it may be absorbed, produce a photon of light, or another electron with a similar energy.

If you remove an electron from the surface of a metal, and then accelerate it through a voltage difference of 1 volt, it will gain an energy of 1 eV, (one electron volt). When that electron impacts a metal target, it may release that energy as a photon. The wavelength (colour) of that photon is inversely proportional to its energy.

but straight up knockout and then later form x rays? if yes, then is there a formula to derive the minimum amount of energy needed to do it,...

If you specify the required wavelength, λ, you can work out the voltage difference needed to accelerate the electron to get a photon of that wavelength.
Energy; eV = 1239.84 / λ nm

X-rays have a wavelength of about 30 pm = 0.03 nm, so the required energy is 1239.84 / 0.03 = 41.3 keV, which will require a voltage of 41.3 kV. X-ray machines operate between about 20 kV and 80 kV.

To produce red light, λ = 700 nm. V = 1239.84 / 700 = 1.77 volts.
That is the voltage needed to light a red LED.