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1.
An acronym to remember the order of subshells in an atom. The first subshell is the S subshell, then the P subshell and so fourth.
To remember the acronym, think "Stephen Porks Dead Ferrets" (the name stephen can be replaced with any name starting with 's') provided they are a weiner you know!
Remember the order of subshells kids, use S.P.D.F, Stephen Porks Dead Ferrets
by Leroy The Prophet October 11, 2006