A 100 W bulb converts 10% of its power into light. If each emitted photon has energy 4.00×10−194.00\times10^{-19}4.00×10−19 J, what is the photon emission rate?
4.00×10194.00\times10^{19}4.00×1019 s−1^{-1}−1
2.50×10192.50\times10^{19}2.50×1019 s−1^{-1}−1
2.50×10202.50\times10^{20}2.50×1020 s−1^{-1}−1
2.50×10182.50\times10^{18}2.50×1018 s−1^{-1}−1