Chinese 發問於 科學及數學化學 · 10 年 前


1. Is electronegativity EXACTLY the same as effective nuclear charge? If no, what is the difference?

2. Do the effective nuclear charge of the elements in the same group are all the same?

Thank you!

1 個解答

  • 10 年 前

    1. no. electronegativity mainly describes atom's affinity to INCOMING electrons, or to say, the tendency to form anion; while effective nuclear charge mainly describes atoms' affinity to its ORIGINAL electrons, or, reluctance to become cation.

    eg. helium has very high effective nuclear charge to its electrons due to minimal shielding effect. however, as any incoming electrons have to be accomodated in 2s orbital, the ion formed would not be stable. thus its electronegativity is very low.

    most likely, concept of electronegativity is used to account for bond polarity, H-bond and stability of ions; effective nuclaer charge is used in atom/ion size, ionization energies.

    2. no way! electrostatic attraction weakens as distance between two objects increases. moreover, going down the group means more inner electron shells. shielding effect owing to inner shells strengthens, thus effective nuclear charge would decrease down the group.

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