I need help with this please: How much energy would be required to vaporize 45.0 grams of water?

What best discribes the relationship between wavelength and frequency in a electromagnetic wave

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 organs inside the body and how they function together