化学式是化学学习的重要工具,在初中化学学科学习中起着承上启下的作用,它是初学者的一个难点,也是必须掌握的重点。帮助学生快速掌握化学式的书写,对其今后的学习意义颇大。一、微调教材1.人教版教材中,化学式的书写放在第四章第四节,教学中是可以略做调整的,在上完第三章后马上学习化学式的书写。2.对纯净物的分类,教材中安排在第四章第三节,教学中可以 Chemical formula is an important tool of chemistry learning. It plays a role in junior high school chemistry study. It is a difficult point for beginners and a must-master point. Help students to quickly grasp the chemical writing, for its future learning is quite significant. First, the fine-tuning teaching materials 1. People’s Education Edition teaching materials, chemical writing on the fourth quarter of Chapter IV, the teaching can be slightly adjusted, the third chapter immediately after learning chemical writing. 2. The classification of pure things, teaching materials arranged in the third chapter of Chapter IV, teaching can