1. The most electronegative element is O (a)
2. The element that exhibits Greatest number of oxidation states is N (e)
3. The Smallest ionic radius for its most common ion is found for Mg (d)
1. Electronegativity is tendency of an atom to attract shared pair of electrons. Across a period, it increases from left to right while in a group, it decreases as we move down. The most electronegative elements are found in the top right of the periodic table because of the increase in effective nuclear charges. Hence, O is most electronegative element.
2. Oxidation state is the total number of electrons that an atom can either gain or loss to form a chemical bond. N exhibits a wide range of oxidation states from -3 to +5 because of half filled p orbital which is more stable.
3. Ionic radius is the radius of a monatomic ion in an ionic crystal structure. [tex]Mg^{2+}[/tex] has higher number of protons that will attract the negatively charged valence electrons to a greater extent hence shortening the distance.
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