水的组成、分子和原子(国外英文资料).docVIP

水的组成、分子和原子(国外英文资料) [learning goal integration] According to the water experiment, the composition of water. Understand the difference between a single and a compound. Understand the processes and methods of the human understanding of the physical world. Knowledge is made up of tiny particles, such as molecules and atoms. They are the smallest particles that hold the chemical properties of matter; Atoms are the smallest particles of chemical change. The basic characteristics of the molecule and explain the phenomenon Cultivate abstract thinking, imagination, analysis and reasoning. Emphasis: water composition according to the electrolytic water experiment. Use the idea of molecules and atoms to explain some phenomena. Difficulty: the distinction between single and chemical compounds; Understanding of molecular and atomic concepts. [a] Knowledge: electrolysis of water Laboratory instruments: water electrolyzer (or sink and test tube), dc power supply, and alcohol lamp. Experimental drugs: water, sodium hydroxide (or dilute sulphuric acid). 3. The experimental operation: as shown in figure 7-1 and 7-2, in the water electrolyzer (or tube) filled with water, water to add a small amount of sodium hydroxide (or dilute sulphuric acid), connected to the power supply. Experiment: there is a bubble in the electrode, and after a period of time there is less gas and more gas. The positive and negative gas volume ratios are about 1:2. Check the gas: as shown in figure 7-2, test the gas in test tube 1 with a wood strip with Mars. When the gas in test tube 2 approaches the flame, the gas burns and the flame is light blue, indicating hydrogen. The result of the experiment is that the water is produced by the direct current, which produces hydrogen and oxygen. Words: hydrogen plus oxygen H2O H2 O2 Experimental analysis: hydrogen is made up of hydrogen and oxygen is made up of oxygen. This means that water is not made up of one element but hydrogen and oxygen. [bullet point interpreta