## Chemistry and Chemical Reactivity (9th Edition)

a) $Si_2^-$ has 9 valence electrons: $[core]\ (\sigma_{3s})^2\ (\sigma_{3s}^*)^2\ (\pi_{3p})^4\ (\sigma_{3p})^1$ b) It's paramagnetic because it has one unpaired electron. c) $\sigma_{3p}$