Question

If degeneracy of first excited state of hydrogen atom is 4 then what is the degenaracy of 2nd excited state of lithium +

Answer 1

Answer:

Single electron species don't follow the [ n+l ]rule. [(n+l) rule is the rule to find the energy order of the subshells], thus hydrogen being a single electron specie has all its subshells of equal energy in n=3. thus degeneracy( number of orbitals of equal energy for the electron to be excited in ) is 9 {1 s orbital+3p orbitals +5d orbitals}

however hydride ion has a configuration of 1s(2)

FIRST EXCITED STATE: 1s(1) 2s(1)

SECOND EXCITED STATE:1s(1) 2s(0) 2p(1)

we excite the electron form s subshell to p subshell .but yeah..we have 3 p orbitals of equal energy for the electron to be put in !

and this solves the problem ..the answer is 3 !er:

Explanation: