Which statement best distinguishes between core and valence electrons for a neutral…
CHEMISTRY · Single correct · AP · Chemistry · Atomic Structure and Properties · Atomic Structure and Properties
Problem
Which statement best distinguishes between core and valence electrons for a neutral phosphorus atom?
(a) Phosphorus has 3 valence electrons because only the electrons in the 3p subshell lie in the outermost shell; the filled 3s subshell and all lower shells are core electrons.
(b) Phosphorus possesses 8 valence electrons—the number required for an octet—so the remaining 7 electrons are considered core electrons.
(c) Phosphorus has 5 valence electrons, all of which occupy orbitals in the n=3 shell; the 10 electrons in the n=1 and n=2 shells are core electrons.
(d) Phosphorus has 2 valence electrons corresponding to its 3s electrons, whereas the 3p and all lower-energy electrons are classified as core electrons.