On this table I realized that elemental potassium could adopt oxidation states of -1, 0, and +1.
Does this mean that elemental potassium can function as both an oxidizer and a reducer? I understand that oxidizers are reduced (gain electrons), and that reducers are oxidized (lose electrons). How can potassium anion be formed? The potassium anion must be extremely unstable due to potassium's extremely low electronegativity, correct?
Also in what compound does potassium actually have a negative oxidation state?