The following electron configurations represent excited states. Identify the
element, and write its ground-state condensed electron configuration.
(a) \(1 s^{2} 2 s^{2} 3 p^{2} 4 p^{1},\) (b) \([\mathrm{Ar}] 3 d^{10} 4 s^{1} 4
p^{4} 5 s^{1}\),
(c) \([\mathrm{Kr}] 4 d^{6} 5 s^{2} 5 p^{1}\)
(a) Determine which elements emit radiation in the visible part of the
spectrum. (b) Which element emits photons of highest energy? Of lowest energy?
(c) When burned, a sample of an unknown substance is found to emit light of
frequency \(6.59 \times 10^{14} \mathrm{~s}^{-1}\). Which of these elements is
probably in the sample?