What volume of carbon dioxide gas (in mL) is produced when 299 mL
of acetylene gas undergoes complete combustion? Assume all
reactant and product volumes are measured at SATP.

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?