Research On Students' Cognition In Periodic Law Of Elements

The Periodic Law of elements is the important cornerstone in the chemistry world. In the chemical science system, the Periodic Law can guide scientific research. Meanwhile, the subject thinking in the Periodic Law could help the students to construct the system of chemistry. And it is the important basis to infer material properties.The students in the high school learn the knowledge of the Periodic Law. The systems they construct are different. Some students can analyze from the structural perspective. While the others just retell the law.The research answers the following questions:(1) How do the students understand the concepts about the Periodic Law? Mainly the attention should be paid to metallicity and so on.(2) What kind of cognition does the students have about the Periodic Law? How does the relevant knowledge link up?(3) What is the influence of different congnition about the Periodic Law? What is thinking process in the problem-solving process?The research methods this research adopts are the group testing and individual interviews. The test tool is a piece of test about the periodic law which is made by myself.The conclusions of this research are as follows:(1) There are two levels about the students's cognition of the periodic law. Most of the students present the formulation the same as the teacher tells and the teaching material appears. Just a few of the students analyze in the view of the structure.(2) Most of the students often confuse some concepts of the periodic low in several groups. For example, some students think that the metallic of the elements is the same as the activity of the simple metal.(3) The understanding of the subject ideological is not thorough. It is difficult to study more effectively by means of the subject ideological.