Research On Comprehensive Inquiry Studying Design Of Calorifics In Middle School

In the middle school thermal knowledge review stage,teachers need to guide and help students understand deeply and understand the content that students will not apply and understand,so as to achieve the purpose of comprehensively applying the knowledge learned to solve practical problems in life.In the study design of this article,first of all creates a specific situation : boil the eggs with an egg cooker.In such an activity,Students are confused about the phenomenon of "why the water in the egg cooker is dried and the power is automatically cut off,and the eggs are cooked." In order to solve this complicated problem,students should start with simple problems.By comparing and analyzing the boiling of water from room temperature to 100 ° C,and the heat that needs to be absorbed from boiling to drying,the students' cognition conflicts,the boiling process needs to continue to absorb heat,but the temperature of boiling water is the same as the temperature at which vaporization forms water vapor,where is the large amount of heat absorbed?Students consider the vaporization of water from the theory of molecular motion.After that,the students discuss about putting an egg in the egg cooker.Will the heating time be prolonged?Through qualitative analysis and quantitative calculation,they knows to put an egg and heat it,the time is extended by about 1 minute.Students think about cooking an egg,how many grams of water vapor liquefaction to provide energy? Through the calculation,analysis and solution of this problem,the related knowledge of vaporization heat is further applied.After a series of discussions,the students still have doubts in their hearts.Why is the water dried and the egg is just 100°C,so it is cooked? Students can think about and analyze the problem from the opposite side,knowing that if the surface of the egg does not reach 100°C,there will always be water vapor liquefied into water and re-drop into the egg cooker.In general,through this comprehensive inquiry learning activity,it is hoped that students can not only master the knowledge of molecular dynamics theory more thoroughly,but also hope that students can combine the knowledge of energy conservation,liquefaction,vaporization and molecular dynamics theory to solve practical problems.