Final answer:
The energy of an ultraviolet photon with a wavelength of 160 nm is calculated using the formula E = hc / λ and is approximately 1.2 × 10^-18 joules when expressed to two significant figures.
Step-by-step explanation:
To calculate the energy of an ultraviolet photon with a wavelength of 160 nm, we can use the equation E = hc / λ, where E is the energy in joules, h is Planck's constant (6.63 × 10-34 J·s), c is the speed of light in a vacuum (3.00 × 108 m/s), and λ is the wavelength in meters. First, we convert the wavelength from nanometers to meters by dividing by 1,000,000,000, then we plug the values into the equation:
E = (6.63 × 10-34 J·s) * (3.00 × 108 m/s) / (160 × 10-9 m)
After performing the calculation, we find that the energy of the photon is approximately:
E = 1.24 × 10-18 J
Thus, the energy of an ultraviolet photon with a wavelength of 160 nm, expressed to two significant figures, is 1.2 × 10-18 J.