What is non-science? Philosophy or art.

Which subatomic particle has a negative charge

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?

Efficiency is the ratio of to for a system a)power in to power in b)power in to power out c) power out to power out d) power out to power in