1.3 BONDING IN CERAMICS:
The properties and the way its atoms are arranged are determined primarily by the nature and directionality of interatomic bonds. If the bond is strong, those are the primary bonds. The primary bonds may be ionic, covalent, or metallic.
Van der Waals and hydrogen bonds are secondary bonds, and they are weaker than the primary bonds. Ceramics contain two types of primary bonds—ionic and covalent. There a few ceramics that contain a third type of primary bond (e.g., the metallic bond). For example, in Fe3C, the bond is partly ionic.
Ionic compounds generally form between very active metallic elements and active nonmetals. Thus, the metals mostly involved in the formation of ceramics by ionic bonding are those from groups IA, IIA, and part of IIIA, as well as some of the transition metals. Moreover, the most active nonmetals of groups VII A and VIA form ionic bonding. For covalent bonding to occur, ionic bonding should be unfavorable to form. This unfavorability can be semi-quantified using a scale of relative electronegativity. Pauling proposed this scale.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
الرجوع الى لوحة التحكم
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