Answer:
109.8 nm
Explanation:
The first ionization energy of a hydrogen atom is,
[tex]E=1.81aJ\\E=1.81\times 10^{-18} J[/tex]
And Plank's constant, [tex]h=6.626\times 10^{-34}Js[/tex]
And the speed is, [tex]c=3\times 10^{8}m/s[/tex]
Now the formula for energy will be,
[tex]E=\frac{hc}{\lambda}[/tex]
Put all the variable after rearranging for lambda.
[tex]\lambda=\frac{6.626\times 10^{-34}Js(3\times 10^{8}m/s)}{1.81\times 10^{-18} J} \\\lambda=10.98\times10^{-8}m\\\lambda=109.8\times 10^{-9}m\\\lambda=109.8 nm[/tex]
Therefore the wavelength of light is 109.8 nm to ionize a carbon atom .