Can somebody please help me here ? i wanna make sure of my answer..

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

Which statement best describes the flow of energy in this scenario

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?