Consider a different situation. An ice cube is placed in a cup, and the cup is filled to the brim with mineral oil, which has a density of 0.8 g/cm3. The density of ice is about 9% less than the density of liquid water, which is about 1 g/cm3. After the ice melts, what will happen to the level of the water/oil mixture in the cup

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?