Knowing that 20 is d what would i write for an explanation to see how i got that answer?

What is the mass defect of a mole of nuclei with 1.8 x 10^15 j/mol binding energy?

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 density of benzene at 15 °c is 0.8787 g/ml. calculate the mass of 0.1500 l of benzene at this temperature. enter your answer in terms of grams