Answer: \(3.28\times 10^{-19}\ \text{J}\) (about \(2.05\ \text{eV}\))
Explanation: Use \(E=\dfrac{hc}{\lambda}\). With \(h=6.62607015\times10^{-34}\ \text{J·s}\), \(c=2.99792458\times10^8\ \text{m/s}\), and \(\lambda=6057.8\ \text{Å}=6.0578\times10^{-7}\ \text{m}\),
Convert to electronvolts: \(E/\!e \approx 3.28\times10^{-19}\ \text{J}/1.602176634\times10^{-19}\ \text{J/eV}\approx 2.05\ \text{eV}.\)