Two charged particles repel each other with a force of F. How would the magnitude of this force change if the charge on one of the particles was doubled?

- it would decrease to one-fourth of what it was.

- it would decrease to half of what it was.

- it would increase to four times what it was.

- it would increase to twice what it was.

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?