Question

The energy required to remove an electron from metal $ X $ is $ E = 3.31 \times 10^{-20}\, J $ . Calculate the maximum wavelength of light that can photo eject an electron from metal $ X $

• A. $ 6.01 \times 10^{-6}\, m $
• B. $ 3.10 \times 10^{-3}\, m $
• C. $ 5.01 \times 10^{-6}\, m $
• D. None of these

Answer 1

Answer: (A)

Energy, $E=\frac{hc}{\lambda}$
or $\lambda=\frac{hc}{E}=\frac{6.626\times10^{-34}\times3\times10^{8}}{3.31\times10^{-20}}$
$=6.00\times10^{-6}\,m$