\(E = \frac {hc}\lambda\)
where,
h = planck's constant
c = velocity of light
\(\lambda\) = wavelength of photon
\(E = \frac{6.6 \times 10^{-34}\times3\times 10^8}{6000\times 10^{-10}}\)
\(= \frac {19.8 \times 10^{-26}}{6\times 10^{-7}}\)
\(= 3.3 \times 10^{-19}\) joule