Of micro-chemical experiment to improve scientific literacy of students

Abstract: Chemistry is a laboratory-based disciplines, experimental micro-chemical experiments with a larger than conventional superiority author combines his own experience teaching a number of waste materials and equipment used to produce a variety of mini-laboratory equipment. Experimental exploration with micro- mobilize interest in learning, active participation, development of innovative thinking, rigorous scholarship to improve the scientific attitude, to develop good habits of thrift and environmental awareness, improve their scientific literacy.

Keywords: micro-experiment, to explore the experiment, green chemistry, experimental design, scientific literacy

Chemistry is a laboratory-based science. In 1998 the Nobel Prize awarded Cohen (U.S. and Popper (British), in recognition of their field of theoretical chemistry has made a significant contribution to their experimental and theoretical work to make concerted efforts to explore the nature of the molecular system, causing the entire field of chemistry is undergoing a revolutionary change. the future direction of development is no longer a chemical experience, which also is no longer a purely experimental science, but the combination of both, under the guidance of the theory experiment, in the experiment continue to improve the theory.

Micro-experiments in the last 20 years, rapid development of new chemical experimental model, that is, with minimal chemical reagents in micro chemical apparatus plant in chemical experiments to obtain the required information on experimental methods and techniques. The reagent is a conventional test one-tenth to one-thousandth of the amount. In junior high school chemistry teaching, the use of mini-experiments to explore, both to develop students 'thinking, students hands-on and ability to design experiments, but also can improve students' scientific literacy. Author on this aspect, combined with their experience and practice Brief Discussion of two.

First, the use of mini-experiments to mobilize interest in learning, stimulate the curiosity of students
Interest is the best teacher, chemistry experiment is to stimulate interest in learning the best way to start each school year, the first class can be lively, interesting "chemical games" class and I am the first sessions the students to show the students made small and , beautiful lovely miniature chemical laboratory instruments "treasures", re-use of micro-chemical laboratory instruments and conventional instruments, teachers and students on the same stage performing interesting experiments and small chemical magic, like "fairy paper manifestation", "fire and water compatible", "Magic lighting rod "," water change milk "," Xingxingdiandeng, "" Midas touch ", etc ... These students are wonderful mysterious phenomenon attracted, as if into a mythical world, mesmerized: I did not thought, with waste materials around the system out of these "little things" so much as magic. Although the game will be ended, but the study of chemical mind has been opened, they got Yi Xie wait immediately discarded items, making a few "small things, "show yourself the power of the student deeply felt: chemical is not far away, on our side.

Second, the use of mini-experiments to explore the development of thinking, to improve student awareness of innovation
Traditional classroom demonstration, many students only see clearly, did not understand, just "listen" experiment because of the teacher's "do it" is not conducive to the cultivation of creative ability of micro experiments to explore the changes the "one person, do we see "situation, so that the vast majority of students have hands-on opportunity to experiment, so that the" passive waiting "approach to learning, to" take the initiative to explore the "learning mode for students in the classroom to get started and use the brain not only enhance the perceptions of students conducive to the understanding of new knowledge, memory, and the development of student thinking, to develop students' horizons and increase innovation.

Such as the use of hydrogen peroxide and manganese dioxide mixed system of oxygen when a student accidentally drops of hydrogen peroxide on the ground, found a large number of bubbles, that "looking for hydrogen peroxide decomposition catalyst" in the subject. Students have responded, positive action, eye drops to use discarded plastic bottles (the absorption of penicillin bottles of hydrogen peroxide and equipment, looking for the catalyst in the interest group wrap-up meeting, the students were eager to speak, and with experiments to prove their own ideas, both active classroom atmosphere, but also the formation of a scientific method of inquiry. now part of the students to explore the results are reported as follows:
Li Hua students apply eye drops drip plates and plastic bottles (the absorption of hydrogen peroxide catalytic decomposition of hydrogen peroxide to identify various substances.

Zhang Mingming student said: Last year I had a toothache disease, the doctor told me to drink a small amount of hydrogen peroxide disinfection, the results of the oral cavity full of air bubbles. Mouth what material to make hydrogen peroxide decomposition it? I asked a doctor to know: the organization of enzymes in the blood encounter with hydrogen peroxide to decompose to produce oxygen, oxidizing bacteria in vivo bactericidal activity groups play a role. Organization of the human body enzymes - catalase is the decomposition of the catalyst.

Lei handsome classmate, said: Since the organization of the human body enzymes break down hydrogen peroxide decomposition, the presence of animals catalase? We use animal organs - liver to test yourself! (Experimental design process (through the experiments can be concluded: liver can also be a catalyst for its decomposition. Links to free download http://www.hi138.com
Yi Ge-day student said: I know that online access to materials, copper sulfate solution, ferric chloride solution can also be catalytic decomposition of hydrogen peroxide, which we can not verify the catalytic effect is better? ... ...

Third, the use of mini-experiments to explore the active participation, hands-on awareness
Not rely on traditional experimental teaching students a large number of experimental operation (appearance to experience, to grasp, to thinking, but by the teacher demonstration, the students remember, be applied mechanically to the application, students do not do experiments, not to mention hands-on ability, while enable each student to explore the micro-experiment can be under the guidance of teachers, according to the wishes of their own to independently test and improve the hands-on awareness, foster experimental capabilities.

The students familiar with basic chemical equipment and chemical operations, the author has let go of a student, to guide and encourage them to use the waste of life to carry out small production, small exploration activities, such as eye drops to use waste plastic bottles, plastic straws (or depletion oil pen core made of multi-dropper, the use of grass coral lozenge made of transparent micro-well plate vacuum hole hard plastic plates, using a small test tube, plastic bottle of eye drops, plastic straw, made of a small centrifuge tubes, etc. sets of white phosphorus and oxygen reaction test device, using a small bottle fitted penicillin, plastic eye drops bottles, plastic straws, a small bottle fitted a new reed made of a system of carbon dioxide and other experimental devices, the use of the test substance produced musical greeting cards conductivity of the experimental device, also made it easy to use "conductive pen." student production of these instruments, although some rough, but it can avoid some weaknesses in conventional glass apparatus, even if the damage is not easy to play touch in the specified time micro-instruments within the production range, then the appropriate allocation of students to a variety of drugs, let it put into their own mini-experiment box in the spare time, even at home can conduct experiments to explore, hands-on experiments to enhance the students the opportunity to improve the students design, appreciation and creative spirit, but also enriched the content of student activities, lesson.

Fourth, the use of mini-experiments to explore the highlights of experimental phenomena, raise awareness of thrift
Micro-chemistry experiments than conventional experiments to reduce or reduction, nor is the complement to conventional experiments, but not with the conventional test of the opposition, but in the miniaturization of the experimental conditions re-design and exploration, to achieve with minimal reagent to obtain as much experimental information with the experimental drug with less, less reaction products, the experiment will not cause danger, the use of the instrument is simple, fast reaction rate, the experimental characteristics of the phenomenon was not only save time, improve efficiency, experiments can accurately obtain the information, can increase students' awareness of thrift below in recent years, the author of several groups to guide students to design experiments to explore the chemistry of the micro-icon.

Fifth, to explore the use of mini-experiments to reduce pollution, improve environmental awareness of students
Green chemistry, also known as environmentally sound chemical, environment-friendly chemical or cleaning chemicals, chemical pollution is popular for its simply to eliminate sources of pollution, zero emissions and zero pollution in the chemical experiments often produce some of the contaminated lab environment affect the physical and mental health of teachers and students, while the use of mini-experiments to explore, the reagents with less instruments miniaturization, the reaction generated when the exhaust gas, waste, less the amount of waste material, and the exhaust gas, waste and other absorption and processing are also easier, especially organic experiment flammable, explosive, toxic substances, particularly the use of mini-experiments to explore, experiment, can greatly reduce the burning, explosion, poisoning risk, ensure the security of personal and experimental, but also greatly reduce the chemical experiments on the surrounding environment pollution, and raise their environmental awareness.

Such as concentrated nitric acid and copper experiment, due to produce more highly toxic gas NO2 can not eliminate the serious pollution of the environment by the four experiments under the Group plans can be generated in response to NO2 is limited to within the micro-gas generator , was absorbed by NaOH solution can fundamentally solve the problem of environmental pollution. Another example to explore the conditions of combustion, due to a large amount of burning white phosphorus white smoke - the air polluting phosphorus pentoxide, with water as generate metaphosphoric acid, leading to emphysema and other diseases, with the following diagram B experiment can effectively control the emission of pollutants, to protect the health of teachers and students.

References
[1] Meng XW, Li Chunxiang. The development of micro-chemistry experiments and its significance [J]. Bio-magnetism, 2005, (3
[2] Song Quang Tri. Micro-chemistry experiments in the curriculum in practice [J]. teaching apparatus and experiments, 2004, (1
[3] Gui-Bin Jiang. Review and Prospect of environmental chemistry [J]. Chemistry, 1999, (11:14 ~ 15

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