Polarizing Power [ENDORSED]

[Karolina herrera1F]

If the cations Mg^+2 and Fe^3+ why would the Mg^+2 be greater?

[Jeril Joseph 1B]

I hope this explanation helps. So, I believe this question is related to polarizing power. So, the cations that tend to have high polarizing power are the cations that have electrons concentrated near the nucleus(so the upper periods). With Mg2+, the cation will satisfy an octet with electrons concentrated towards the nucleus.

[Chem_Mod]

The above Q and A was slightly edited for clarification.

Fe3+ has higher charge and therefore higher polarizing power compared to Mg2+.
Higher the charge typically results in higher polarizing power, dominating the difference in size (which is another factor considered in polarizing power).