Elements A and B are consecutive members of the same period
CHEMISTRY · Single correct · AP · Chemistry · Atomic Structure and Properties · Atomic Structure and Properties
Problem
Elements A and B are consecutive members of the same period. The valence peak of B appears at a higher binding energy than that of A, while the heights of the inner-shell peaks are unchanged. Which statement best explains this observation?
(a) B has more shielding electrons than A, so its valence electrons are held more tightly to the nucleus, increasing their binding energy.
(b) Because B has the larger atomic radius, its valence electrons are closer to the nucleus, resulting in a higher binding energy peak.
(c) B has a greater effective nuclear charge than A, so its valence electrons experience a stronger attraction to the nucleus.
(d) Being farther to the right in the period, B has more valence–valence electron repulsion, which raises the energy required to remove those electrons and therefore the binding energy observed.