What is the change of state from gas to liquid

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?

The polarity of an oxygen-hydrogen bond is higher than the polarity of a nitrogen-hydrogen bond, allowing amines to be more soluble than alcohols.

What percentage of energy used in the u.s is produced from fossil fuels