In which region of the electromagnetic spectrum do we find the energy to fully ionize hydrogen?

Question

A) Radio
B) Infrared
C) Visible
D) Ultra-violet
E) X-ray

I want to know how you would go about doing this question; I know we need to find the wavelength, but what exactly is the connection between wavelength and energy required?

Answer 1

Energy= boltzmanns constant*speedlight/wavelength

Energy= inonization energy
wavelength= incoming light

solve for wavelength.

Remember: MEMORIZE
Planck's equation
energy= boltzmannconstant*frequency

Answer 2

E)X-Ray region