The equation for the energy of the electron in the hydrogen atom is given in your text(s) as E= - 2.18 x 10^-18J x (1/n_f^2 - 1/n_i^2). However the actual equation is -2.18 x 10^-18j x Z^2(1/n_f^2 - 1/n_i^2) where Z= nuclear charge (number of protons in the nucleus). It is important to note that this equation only works for single electron species. With this equation in mind, answer the following question.
An emission line in the hydrogen spectrum appears in the infrared region at 956 nm. What transition produced this line? Clearly indicate both nf and ni.