determine the resultant amplitude of two out of phase waves one with an amplitude of 0.5 and the other of 3

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?

Why are graphs useful when interpreting data

What’s #16 asking me and how do i solve it?