If the radial velocity of a galaxy is 2200 km/s per million parsecs, then what is its distance from the sun: in light years and kilometers ?​

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?

The necleus of an atom is made up of what subatomic particles?

Emergent properties of living systems are defined as properties that .