The species contain unpaired electron will show paramagnetic nature. In the given species only KO2 has unpaired electron as it has 17 Valency electrons. (odd number of electrons). i.e. K+ and O2−(0+17=17) All other species are diamagnetic in nature (a)SiO2→Si4++O22− (Diamagnetic) (b) TiO2→Ti4++O22+ (Diamagnetic) (c) BaO2→Ba2++O22− (Diamagnetic)