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Elements and Compounds

Why is the ionic radii of a boron 3 ion larger than a carbon 4 ion?


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November 26, 2008 9:38PM

The ionic radii is affected by the number of electrons and the number of protons. In the case of Boron+3 and Carbon+4, the number of electrons are equal (2). Thus, it is a matter of looking at the nucleus. Boron has 5 protons while Carbon has 6 protons. The protons acts an attractive force to pull the electrons towards the nucleus. Therefore, carbon has a higher proton to electron ratio meaning it is pulling the electrons in more than boron. Hence, boron has a larger ionic radii than carbon.