A Study On The Cognitive Development Of The Concept Of "Atomic Structure" Of Middle School Students

Cognitive development is the development of human perception, attention, thinking, imagination, cognitive process and quality, and it is the development of cognitive structure and knowledge accuracy etc. The data shows that the study of cognitive development in the field of chemistry education in view of the atomic structure of knowledge is not inadequate. To this end, the author firstly combined with relevant information at home and abroad, further elaborated on the connotation and impact factors of cognitive development and analyzed of the problems related to the concept of high school chemistry learning of atomic structure, then, around the "atomic structure" concept of design-related issues, with case studies and a wide range of test this way, to probe cognitive development status which atomic structure knowledge for middle school students detection in the process of learning, the author from the perspective of cognitive process and cognitive result, analysis to the perceptual thinking quality and ability of students to the wealth of knowledge and the accuracy of cognitive structure and cognitive Angle. The results showed:For the development of sensory perception:(1)The words and chart of atomic structure knowledge in the process of perception and awareness, the junior grade three and the senior grade one students lack the microscopic characterization consciousness from the atomic structure level, and the senior grade two and the grade senior three students have apparent change, but the senior grade three students are more specific micro characterization.(2) The same overall cognitive level with those about atomic structure in the senior grade two, while the knowledge of extra-nuclear electron increases gradually. The consciousness of quantum mechanics models is constructed, and the perception of atomic structure is from two-dimensional to three-dimensional object. The electron clouds model is used to explain to the atomic structure by students in the senior grade three.(3)With the increase of the grade, students’conversion rate gradually increased from structure to nature, the transformation of the senior grade three is the largest.(4) On the representation of atomic structure, the junior grade three students is given priority to with language characterization and model characterization, mainly through the model characterization of the planets model to represent. The high school students’Symbolic characterization is predominant, the senior grade two and three students’ model representation of ratio is rising, and they used electronic-cloud-model to represent.For the thinking quality and ability of development:(1) The senior grade two and three students’ thinking profundity is superior to the senior grade one and the junior grade three, mainly reflected in the construction of relationships between concepts.(2) With the increase of knowledge, the students pay more attention to get gradually information about the chemical symbols. The abstraction thinking ability and the synthetical thinking ability will be improved for students.(3) Compared with students of the junior grade three and the senior grade three, the students have good critical thinking in the senior grade one and two. It is the main problem that the students’ thinking is restricted to the textbook knowledge.(4) With the increase of knowledge, the method of learning strategies about simple memory is used at times. The number of students using the associative method keeps still. The number of students using modeling method increases gradually.For the extensive and accuracy aspects of knowledge:(1) Compare with students in the other grades, students of the senior grade two get more knowledge about the association about the concepts of atomic, nuclear electronics and nuclear, and the information average value is maximum. Compare with students in the other grades, the students have extensive knowledge of association about the ion concept the in the senior grade three.(2) With the increase of knowledge, the little fuzzy concepts decrease for students. The number of fuzzy concepts is maximum for students of the senior grade two. The percent of fuzzy concepts decreases for students of the senior grade three.For the development aspects of cognitive structure and cognitive perspective:(1) With the increase of knowledge, the knowledge structure of students gradually complete. The knowledge chain of nucleus and ion increases slowly for students in the senior high school. The knowledge chain of extra-nuclear electron increases quickly for students in the senior grades one and two, but the increasing amplitude of it reduces for students of the senior grade three.(2) The cognitive perspective of the junior school students is isolated, macroscopical and statical. For the senior school students, the cognitive perspective is expanded gradually. The cognitive perspective will be associative, microscopic, dynamic and symbolic representation.On the basis of the exploration to the student cognition development, the author puts forwar d three suggestions for teaching:paying attention to the education chemistry discipline idea, dev eloping the students’ thinking through a variety of ways, paying attention to the cultivation of students’ consciousness of modeling and modeling ability in teaching.