1. the sum of two numbers is 90. their difference is 18. find the numbers. a(40, 22) b(45, 45) c(36, 54) d(27, 63) e (40, 50) f (72, 90)

Awavelength of 610 nm was found to be the most intense wavelength emitted by copper. answer the following questions about this wavelength of light. a) what is this wavelength in cm? b) what is the frequency that corresponds to this wavelength? c) what is the energy of light of this wavelength? d) what is the wavenumber corresponding to this wavelength?