Which of the following transitions (in a hydrogen atom) represent emission of the longest wavelength photon?
a) n = 1 to n = 2
b) n = 3 to n = 1
c) n = 3 to n = 4
d) n = 4 to n = 2
e) n = 5 to n = 4

E) n = 5 to n = 4

Explanation:

Since the question stated that it is an emission process, options involving increase in transitions are to be ignored. This means option a and b are to be ignored as they refer to absorption.

We are left with three options.

The second option can be dropped because of the huge energy gap involved. Any drop into level one is in the ultraviolet, which are short wavelengths.

We are left with two options now.

The fouth is a transition between two levels, ehich means extra energy involved.

The fifth is a transition between just one level, which means lesser energy is involed.

Energy and wavelength are inversely proportional to each other, so the higher the energy, the lesser the wavelenth.

The emission with the longest wavelength (or, least energy) is the last option, the 5 to 4 transition.

it is the most commonly accepted one

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.