📚 Comparing Metallic and Non-metallic Character | 金属性与非金属性强弱比较
This article explains how to compare the metallic and non-metallic character of elements using periodic trends, ionisation energy, electronegativity and redox reactions. These ideas are fundamental for A-level chemistry candidates who need to predict element behaviour and understand periodic relationships.
本文讲解如何利用周期律、电离能、电负性和氧化还原反应来比较元素的金属性与非金属性强弱。这些概念是 A-level 化学学生预测元素行为、理解周期关系的必备基础。
1. Definitions | 定义
Metallic character is the tendency of an element to lose electrons and form positive ions. Metals usually have low ionisation energies, high electrical conductivity, malleability and basic oxides.
金属性是元素失去电子形成正离子的倾向。金属通常具有较低的电离能、良好的导电性、延展性和碱性氧化物。
Non-metallic character is the tendency of an element to gain electrons and form negative ions. Non-metals usually have high electronegativity, acidic oxides and oxidising ability.
非金属性是元素获得电子形成负离子的倾向。非金属通常具有较高的电负性、酸性氧化物和氧化能力。
2. Trends Across a Period | 同周期变化
Across a period from left to right, the nuclear charge increases while the atomic radius decreases. The outer electrons are attracted more strongly, so the tendency to lose electrons falls and the tendency to gain electrons rises.
同一周期从左到右，核电荷增加而原子半径减小。外层电子受到更强的吸引，因此失电子倾向下降，得电子倾向上升。
Consequently, metallic character decreases across a period and non-metallic character increases. In Period 3, Na and Mg are metals, Al is amphoteric, Si is a metalloid, and P, S, Cl are non-metals.
因此，同一周期中金属性减弱而非金属性增强。在第三周期，Na 和 Mg 是金属，Al 呈两性，Si 是准金属，P、S、Cl 是非金属。
3. Trends Down a Group | 同族变化Published by TutorHao | Chemistry Revision Series | aleveler.com
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