Based on predicted trends in the periodic table: Order the following in terms of increasing atomic or ionic radius:
Cd2+
Sn4+
Ag+
In3+
To order the given ions in terms of increasing atomic or ionic radius, we need to consider their positions in the periodic table. Atomic or ionic radius generally increases as we move down a group and decreases as we move across a period from left to right.
Let's analyze each ion in the given list:
1. Cd2+: Cadmium (Cd) is a transition metal that belongs to Group 12 in the periodic table. When it forms a positive ion with a +2 charge, it loses two electrons from its neutral state. As we move down Group 12, the atomic or ionic radius generally increases. So, the Cd2+ ion will have a larger atomic or ionic radius compared to its neutral state.
2. Sn4+: Tin (Sn) is a main group element belonging to Group 14. When it forms a positive ion with a +4 charge, it loses four electrons from its neutral state. Moving down the periodic table within Group 14, the atomic or ionic radius generally increases. Thus, the Sn4+ ion will have a larger atomic or ionic radius compared to its neutral state.
3. Ag+: Silver (Ag) is a transition metal that belongs to Group 11. When it forms a positive ion with a +1 charge, it loses one electron from its neutral state. For transition metals, the atomic or ionic radius remains relatively constant across a period. Therefore, the Ag+ ion will have a smaller atomic or ionic radius compared to its neutral state.
4. In3+: Indium (In) is a main group element belonging to Group 13. When it forms a positive ion with a +3 charge, it loses three electrons from its neutral state. As we move down Group 13 in the periodic table, the atomic or ionic radius generally increases. Hence, the In3+ ion will have a larger atomic or ionic radius compared to its neutral state.
Considering the above analysis, the order of the ions in terms of increasing atomic or ionic radius would be:
Ag+ < Cd2+ < In3+ < Sn4+