Design And Practice Of Seveal Typical Micro-experiments In High School Chemistry

Experiment is the fundamental characteristic and attribute of chemistry,which is of great practical significance to the formation of students' core accomplishment.In chemistry teaching,the curriculum standards and relevant documents have put forward clear requirements and guidance on the establishment of experiments for many times,so as to improve the rate of experiment establishment,so that students can truly achieve the purpose of "learning by doing".Over the years,through continuous practice and improvement,conventional experiments have achieved remarkable results,which have been deeply rooted in people's minds.However,under the time background of student individuality development,cultivation of innovative talents and the green environmental protection awareness,the conventional chemical experiments in the original teaching mode also gradually shows its defects,especially for some experiments with high risk factors,difficult experimental operation,unconspicuous experimental phenomena,low success rate,time consuming and so on,it is more difficult to carry out normally in class.In this context,micro-experiments have gradually attracted people's attention due to their features of small instruments,less drug dosage,less pollution,obvious experimental phenomena,rapid and safe experimental process,and can better make up for the defects of conventional experiments and meet the diverse needs of experimental teaching.This research aims at developing micro-experiments to meet students' "pain points",and the ultimate goal is to promote the "learning-centered" teaching reform.On the basis of consulting and analyzing a large number of relevant literatures,this paper makes clear the status quo of micro-experiment in high school teaching through questionnaire,and summarizes the chemical experiment with great room for improvement.On this basis,the representative of metals,non-metals and organics--"the properties of sodium","the properties of sulfur dioxide" and "the properties of acetylene" were selected respectively for the micro-experiment design,and learning activity targets was established step by step,and the effect was evaluated according to the learning activity evaluation scale and questionnaire.The practice shows that after a semester,students can gradually evaluate the rationality of the experimental scheme from various aspects of reagent dosage,safety,greenization and utilization rate,and can complete the experimental tasks.In the classroom,students' initiative has been significantly improved and their interaction with teachers has been significantly increased.Micro-experiments can reduce students' fear of chemical experiments.The students' experimental operation in activities gradually changes from non-standard to standard.More and more students are inspired to design their own experimental schemes from the experimental activities,and their practical ability and innovative thinking have been developed.At the same time,the students' love for this experimental method is beyond words,and they hope that the school's enthusiasm for purchasing micro-experiment instruments will rise.Therefore,micro-experiments are promising in promoting learning-centered teaching reform.