[IBM]

is there any difference between 'subshell' and 'orbit' or they are the same? I am confused.

[Enthalpy]

Hi IBM, in what context do you ask all these questions?

Your queries are covered by all textbooks and courses. As it would be counter-productive to replace professors and books by an exchange on the forum, it's no surprise that you obtain few answers. Some people may even get the impression that you didn't bother attend the course nor read the textbooks and hope to obtain the same information from the forum.

But maybe you are not learning this at school?