Ineed this for tomorrow im do bad in this

Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in the n=3 level to an orbital in the n=7 level.

Ase your answer to this question on the information below.hydrocarbons and fissionable nuclei are among the sources used for the production of energy in the united states. a chemical reaction produces much less energy than a nuclear reaction per mole of reactant.the balanced chemical equation below represents the reaction of one molecule of a hydrocarbon with two molecules of oxygen.chemical equation: ch4 + 2o2 → co2 + 2h2o + 1.48 × 10−18 jthe nuclear equation below represents one of the many possible reactions for one fissionable nucleus. in this equation, x represents a missing product.nuclear equation: write an isotopic notation for the missing product represented by x in the nuclear equation.

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )