a rocket can move thrpough outer space where no matter exists for it to push on because the rocket ejects gas molecules these gas molecules push agaisnt the rocket true or false

Idon’t quite understand this problem

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?

An object's buoyant force and weight mean the same thing.a. trueb. false