***hurry*** what is the abbreviation for the si unit for electric potential? v j c u

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?

Acertain radio station broadcasts radio waves that have a wavelength of 298cm what is its broadcast frequency?

Compare the patterns of the two waves shown in the image. which statement is true about these waves?