Question Detail

Page 9 explains: 'The formation of more complicated oxides (i.e. peroxides and superoxides) from the metals releases more energy and makes the system more energetically stable.' It further clarifies: 'This is true for the metals in the lower half of the group where the metal ions are big and have a low charge density.' and 'At the top of the group, the small ions with a higher charge density tend to polarize the more complicated oxide ions to the point of destruction. Therefore, they only form simple oxides.' This indicates that for larger ions with low charge density, complicated oxides are stable.