# Is 2s a subshell or an orbital? [closed]

My textbook says

They will then fill the $$2s$$ subshell, and then the $$2p$$ subshell...

Yet half of ChemSE refers to $$s,p,d,f$$ as "subshells" and the other half seems to refer to $$1s, 2p...$$ for example, as "subshells" as well, even in two answers to the same question.

So is, for example, $$s$$ a subshell, or $$2s$$ a subshell?

• Am I Ivan or Ivan Neretin? – Ivan Neretin Jun 28 at 5:46
• @IvanNeretin You are ИСН:) – andselisk Jun 28 at 8:09
• Terms a shell and a subshell are rather obsolete.2 means the orbital with quantum number n=2, p means the orbital with quantum number l=0. By the particular subshell were considered orbitals with the particular quantum numbers n and l. – Poutnik Jun 28 at 11:53
• @andselisk You knew! – Ivan Neretin Jun 28 at 12:26

Terms a shell and a subshell are rather obsolete. 2 in 2p means the orbital has the quantum number n=2, p in 2p means the orbital has the quantum number $$\ell$$=0.
So s, p, d, f are particular groups of "subshells", each sharing the common value of the quantum number $$\ell$$=0,1,2,3, while 1s, 2p,.. are the particular "subshells".