NEED HELP FAST- WILL GIVE BRAIN.

Choose all the answers that apply. our solar system: is in a spiral galaxy no longer includes pluto is made mostly of empty space is in the andromeda galaxy is the only known system that supports life

Aphoton is absorbed by an electron that is in the n = 3 state of a hydrogen atom, causing the hydrogen atom to become ionized. very far away from the nucleus, the released electron has a velocity of 750,000 m/s. what was the wavelength of the absorbed photon?

Earth has a mass of 5.97 x 1024kg, and a mean radius of 6.38 x 106m. what would be the orbital speed and period of a satellite in orbit 1.44 x 108 m above earth?