Answer
See the answer below.
Work Step by Step
$\Delta E=-Z^2Rhc(1/n_f^2-1/n_i^2)$
With $Z=2, Rhc=2.179\times10^{-18}\ J$
$n_f\rightarrow+\infty, n_i=1$
$\Delta E=8.72\times10^{-18}\ J$
This value is bigger than hydrogen's ionization energy by a factor of $Z^2=4$.
