3. Ionic Compounds

Arrange the following atoms and/or ions in the order of increasing size:Br ^–, Kr, Rb⁺, Sr²⁺.

Arrange the following isoelectronic series in order of decreasing radius:F^–, O^2–, Mg²⁺, Na⁺.

For an isoelectronic series of ions, the ion that is the smallest is always