Moseley's experiment-where he bombarded transitional metals with electrons and measured the energy of photon.

This experiment showed an increase in the energy as atomic number increased. This periodic trend is due to:


a) increasing electron affinity


b) decreasing atomic radius


c) increasing effective nuclear charge


d) increasing electronegativity

Moseley's experiment-where he bombarded transitional metals with electrons and measured the energy of photon.
Your question doesn't make perfect sense. So I'm assuming tha the question part is referring to the energy ejected as photons.





A is wrong since electron affinity is basically the same as electronegativity and as such does not follow a trend that increase with increasing atomic number. Same for D. (trend goes to F)





Atoms do not generally get smaller as they go up in atomic number so b is wrong. (Again trend goes to F)





Therefore the answer must be C. Whicg is true. The nuclear charge does increase as atomic number increases.