SAT Subject Test Chemistry,10 edition

that are already bonded. It characterizes the polarity of the bond, not the likelihood of bond
formation. So choice B is the definition of electronegativity. Choice C is the definition of the
first ionization energy. This is sort of the opposite of electron affinity, since in electron affinity,
electrons are gained; in ionization, electrons are lost. Choice D would give the energy of a
photon released when an electron relaxed from an excited state to a lower-lying state. Since
there are many quantities for this energy, depending on which excited state the electron is in,
it hardly makes a good answer to this question.