[填空题]
An excited H atom ispk ybc3- / ./ bq-j)fdk(lwopezxt+46,wlr y.d7+oc jnhadk 1 in a $6d$ state.
(a) Name all the states $(n, l)$ to which the atom is "allowed" to jump with the emission of a photon.
(b) How many different wavelengths are there (ignoring fine structure)?
