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所在平台: Udemy |
课程主页: https://www.udemy.com/course/p-block-elements/
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**Coursera 课程总结：p 区元素（第一部分）** 本课程详细介绍了元素周期表中位于第13至18族的p区元素。这些元素的外层电子数分别为3到8个，并且最后一个电子填充在p亚层，因此得名p区元素。其通式电子构型为ns²np¹⁻⁶。 **主要知识点：** 1. **电子亲和能：** * 沿p区元素周期表从左到右，电子亲和能增加。 * 从上到下，电子亲和能减小。 * **例外：**第15族元素的电子亲和能异常低，原因是其价电子层具有半满轨道的额外稳定性；第18族（稀有气体）元素的电子亲和能为零，因为它们具有已满的八隅体结构，稳定性极高。 2. **金属性：** * 金属性受原子尺寸和电离能的影响。 * 原子尺寸大、电离能低的元素具有更强的金属性。 * p区元素的金属性分布： * 位于p区左侧的元素金属性最强。 * 位于p区右侧的元素非金属性最强。 * 在两者之间存在一个对角线区域，该区域的元素（类金属）兼具金属性和非金属性。
The right side of the periodic table having group number 13, 14, 15, 16, 17 and 18 are known as p - block elements. These elements have 3, 4, 5, 6, 7 and 8 electrons in their outer most shell, respectively. The last electron of these groups' elementsoccupies the position in p - sub shell that is why these elements are called as p - block elements. Their general electronic configuration is ns2np1-6.Some important properties of p-block(1) Electron affinityElectron affinity increases from left to right along the period amongst the p - block elements and it decreases from top to bottom. But group 15 is having exceptionally low values of electron affinity and is due to extra stability of exactly half filled orbitals in their valence shell. Similarly, elements of group 18 (noble gases) have zero affinities due to presence of complete octet which provides them stability.(2) Metallic CharacterThe metallic character is governed by(i) Size of atoms and(ii) Ionization energy.The elements having bigger size and low ionization energy has a greater metallic character. After combining both the above mentioned factors we observe that the elements with above two properties are located in left corner of p - block and strong non - metallic elements are located at right corner and a diagonal strip of elements separates thus two, having in between properties are called as metalloids.
