Based on the equation: Δ E =-2.0 × 10^-18 J (1/(n_2^2)-1/(n_1^2)) the wavelength of the light that must be absorbed to excite hydrogen electron from…

Based on the equation : $$\Delta \mathrm{E}=-2.0 \times 10^{-18} \mathrm{~J}\left(\frac{1}{\mathrm{n}_2^2}-\frac{1}{\mathrm{n}_1^2}\right) $$ the wavelength of the light that must be absorbed to excite hydrogen electron from level $\displaystyle \mathrm{n}=1$ to level $\displaystyle \mathrm{n}=2$ will be : $\displaystyle \left(h=6.625 \times 10^{-34} \mathrm{Js}, \mathrm{C}=3 \times 10^8 \mathrm{~ms}^{-1}\right)$