For 10 points, name this group of two valence electrons not involved in molecular bonding.
These differ in their S-character between carbanions formed from cubane and cyclopropane, explaining the differing kinetic acidity of those molecules. These can form dative bonds, causing molecules with these to be Lewis bases, and N S Two examples can be inert, explaining the oxidation states found in certain heavy post-transition elements.  These cause the (*) hydrogen bonding observed in water, and VSEPR predicts that these will take up more space than a covalent bonds, leading to trigonal pyramidal and bent molecular geometries. For 10 points, name this group of two valence electrons not involved in molecular bonding.
These differ in their S-character between carbanions formed from cubane and cyclopropane, explaining the differing kinetic acidity of those molecules.
{Lone Pairs} [prompt on "non-bonding electrons" before giveaway]