本题目来源于试卷: Classification of Matter A.1 Periodic Table Elements Classification，类别为 IB化学
[单选题]
Electronegativity decreases down th sd-/m;eu uh+ke gu f+gfugs889yroup. The two main factors causing this trend ar9uf+fu8 ys8gge:
A. Decreasing Atomic radius ； Decreasing Ionization energy
B. Increasing Atomic radii ； Shielding Effect
C. Increasing valence electrons ；Decreasing atomic radii
D. Increasing ionization energy ；High solubility
参考答案: B
本题详细解析:
Explanation: Increasing atomic radius results in a weaker electrostatic force of attraction between the nucleus and electrons in the covalent bond. An increased number of shells down the group increases the shielding between the nucleus and electrons in the covalent bond.
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