It has the characteristics of attracting ferromagnetic substances such as iron, nickel, cobalt and other metals. Magnets can be divided into permanent magnets and soft magnets. Permanent magnets strengthen magnetism, so that the spins of magnetic substances are arranged in a fixed direction with the angular momentum of electrons, while soft magnets are electrified.
Introduction of magnet
The content of this micro-lesson is selected from the third section of the fourth chapter of the third grade science textbook published by Education Press. The overall design theme of this lesson is to carry out teaching with scientific stories, and design experiments by creating situations, causing problems, observing phenomena, analyzing data, revealing laws, applying what they have learned and trying to solve problems.
By running steel balls to create situations, cognitive conflicts are triggered, students' interest in learning is stimulated, and they go through the process of asking questions, exploring experiments and drawing conclusions.
Attach a quiz after class to consolidate the knowledge learned in time. The end of a class does not mean the end of knowledge. Students use the methods learned in this lesson to find out the magnetic poles of other common magnets and apply what they have learned.