Why do hot objects have high temperatures?

What is the independent variable in this investigation? mass volume sample number substance density

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?

From the choices provided below, list the reagent(s) in order that will react with cyclopentanone to form the compound shown below.