7. What is the frequency of UV light that has an energy of 2.39times 10^-18J i 8. What is the wavelength and frequency of photons with an energy of 1.4times 10^-21J 9. What is the energy of a light that has 434 nm? 10. What is the wavelength of a light that has a frequency of 3.42times 10^11Hz

7. To find the frequency of UV light with an energy of , we can use the formula , where is the energy, is Planck's constant ( ), and is the frequency. Rearranging the formula, we get . Plugging in the given values, we have .8. To find the wavelength and frequency of photons with an energy of , we can use the same formula . Rearranging the formula, we get . Plugging in the given values, we have . To find the wavelength, we can use the formula , where is the speed of light ( ) and is the wavelength. Rearranging the formula, we get . Plugging in the values, we have or 142 nm.9. To find the energy of light with a wavelength of 434 nm, we can use the formula , where is Planck's constant, is the speed of light, and is the wavelength. Plugging in the given values, we have .10. To find the wavelength of light with a frequency of , we can use the formula , where is the speed of light and is the frequency. Plugging in the given values, we have or 877 nm.