Which Electrons Belong to the Valence Orbitals?

[el123]

Homework Statement

The electron configuration for three neutral atoms are as follows.

A.1s²2s²2p³
B.1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁵5s²4d⁷
C.1s²2s²2p⁶3s²3p⁶4s²3d⁶

Indicate which are valence orbitals.

The Attempt at a Solution

A.2s²2p³
B.4p⁵4d⁷
C.4s²


Please check if i have this corrrect.

 

[rgscott]

Looks right to me man.

 

[PhaseShifter]

Look at B again.
Which electrons have the highest principal quantum number?