in class, we'll see the energy of a photon is given by hv where v is the frequency of the photon and h is planck's constant. this means that simply noting the wavelength or frequency of a photon is equivalent to stating what its energy is! this has, for better or worse, led to the use of numerous units for specifying the energy of a photon. depending on the region of the electromagnetic spectrum being described, different units are commonly used: a. the energy of photons that fall in the ultraviolet range is typically expressed by giving the photon wavelength in nanometers. for a photon with a wavelength of 133 nm, specify the photon's frequency, v in hertz (hz), and its energy in units of electron volts (ev), joules (j), and wavenumbers (cm1) b. the energy of photons with wavelengths in the mid-infrared range is typically described using wavenumbers (1/x), a quantity proportional to energy. for an ir photon with energy of 1400 cm1, what is the photon's frequency in hertz, its wavelength in nm, and its energy in units of electron volts and joules? c. the energy of photons in the microwave region is traditionally denoted by listing the photon's frequency in mhz. for a photon with a frequency of 45,000 mhz, what is its wavelength in μm and its energy in units of electron volts, joules, and wavenumbers? d. calculate the number of photons emitted in one second by a 60 w sodium lamp that gives off yellow light at 589 nm. this emission band is known as the sodium "d line" and is largely responsible for the yellow color of street lamps!