Does sound travel faster in a warm room or a cold room?

Which graph best represents the relationship between the electric current and the rate at which a magnet is turning inside an electric generator?

Give one example to show that when substances are mixed,it may result in a chemical or a physical change depending on the conditions.

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?