一、精心选题微课是为满足学生进行自主学习需求,经过精心的信息化教学设计,以流媒体形式展示,围绕某个知识点或教学环节而展开的简短、相对完整的教学活动,是一个完整的教学设计。因此,选择什么内容作为主题非常重要。微课视频时间短,教学内容有限,如何让学生在“碎片化”的教学内容中对知识进行完整性的认识呢?通过分析,笔者选择了九年级化学(人教版)第二单元课题一空气这部分内容。在这部分内容中,空气组成的测定是教学的核心问题,也是学生 First, the carefully selected micro-class is to meet the needs of students for independent study, after careful design of information technology, in the form of streaming media, around a knowledge point or teaching links and start a brief, relatively complete teaching activities is A complete teaching design. Therefore, it is very important to choose what is the subject of. How to make students understand the integrity of knowledge in the teaching content of “fragmented”? Through the analysis, I chose the ninth grade chemistry (PEP) second unit A topic of air this part of the content. In this section, the determination of air composition is the core issue of teaching, but also students