Concept:In the periodic table, a diagonal relationship exists between certain elements of the second and third periods. These diagonally adjacent elements have similar sizes and charge densities, leading to similar chemical properties (like electronegativity).
Solution:- Beryllium (Be) is in Period 2, Group IIA.
- Aluminum (Al) is diagonally below it in Period 3, Group IIIA.
- As you move across a period, electronegativity increases, but as you move down a group, it decreases.
- Moving diagonally from Be down to Al, these two opposing trends roughly cancel each other out.
- Due to this diagonal relationship, Beryllium (Be) and Aluminum (Al) share almost identical electronegativity values (approximately 1.5 on the Pauling scale), similar polarizing power, and amphoteric oxides.
Why other options are incorrect:- B: Higher electronegativity (approx 2.0).
- Mg & Na: Much lower electronegativities because they are classic metals located further left.
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