1、 问题:The basic unit of materials is_____, which can bond directly together to form materials, or convert into ions, or assemble into molecules.
2、 问题:Crystalline structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material. We often use ____to illustrate the 3D structure, which is an array of ‘small boxes’ infinitely repeating in three spatial directions.
答案: 【crystal lattice】
3、 问题:Atoms could be bonded in different patterns, we call them chemical bonds. The three main types of chemical bonds are metallic, ionic and ______bonds.
4、 问题:According to chemical composition, materials are usually classified as metals, _, polymers and ______.
5、 问题:The sequence of different scales is macro, mini, meso, ______, nano and atomic.
1、 问题:Metallic materials are mostly ______ i