## Chemistry: The Molecular Science (5th Edition)

The 4.257 $μm$ radiation requires greater energy. 4.257 $μm$ needs $4.666 \times 10^{-20} J$ 15.00 $μm$ needs $1.324 \times 10^{-20} J$
According to Plank's theory, the wavelength is inversely proportional to the energy; therefore, the radiation with smaller wavelength is the one that requires less energy. ------------- μ = $10^{-6}$; $4.257 μm = 4.257 \times 10^{-6}m$ $Energy = \frac{hc}{λ} = \frac{6.626 \times 10^{-34} \times 2.998 \times 10^8}{4.257 \times 10^{-6}} = 4.666 \times 10^{-20} J$ $15.00 μm = 15.00 \times 10^{-6}m$ $Energy = \frac{hc}{λ} = \frac{6.626 \times 10^{-34} \times 2.998 \times 10^8}{15.00 \times 10^{-6}} = 1.324 \times 10^{-20} J$