Teaching design of the big class "The light bulb is on": 1 related knowledge;
The most common function of light bulbs is lighting. The lighting source that emits heat through electric energy was invented by Henry Goebbels (Edison actually found a suitable material, that is, he invented the incandescent lamp with strong practicability, and the light bulb appeared as early as 1854).
Activity objectives:
1, know how to connect the battery with wires to make the light bulb glow, and initially feel that metal can conduct electricity.
2. Cultivate the ability of cooperative inquiry and recording experimental results with symbols.
3. I am interested in conductive phenomena and like to explore with my peers.
Activity preparation:
1, knowledge and experience preparation: children are familiar with the names of experimental materials, and initially understand the shape characteristics of batteries and wires and the types of metals.
2. Material preparation: battery, wire (connected with small light bulb), a piece of cloth for every two children, wool, plastic rope, paper clip, copper key, iron wire, recording paper, pen and power cord; Little bear puppet, battery demonstration comb diagram, large record sheet, etc.
Activity flow:
First, create situations and introduce activities.
Teacher: (showing the little bear puppet) There was a power outage at the little bear's house today. The room is dark. It's really uncomfortable The bear couldn't find the candle, but found a battery and a wire tied with a small light bulb. He wants to install a lamp by himself with these things. What do you think the bear should do to make the light bulb light up?
Second, guide children to explore independently "how to make the light bulb light up".
1. Introduce the experimental materials.
Teacher: Today, let's help Little Bear install electric lights. The teacher prepared batteries, light bulbs and wires. One end of the wire is exposed, and the other end of the wire has been wrapped around the small light bulb. Where should the two ends of the wire be connected to the battery before the light bulb lights up?
2. Explain the operation steps and activity rules.
Teacher: Two children cooperated in the experiment. They can try to make the light bulb glow in different ways.
3. The two children cooperated in the experimental exploration, and the teacher focused on guiding the children to try to connect the batteries in different positions with wires.
4. Guide children to share the experience gained in the exploration collectively through physical demonstration and graphic demonstration.
Third, set up problem situations to guide children to explore the conductive phenomenon of objects independently, and initially perceive that metals can conduct electricity.
1, set the problem scenario.
Teacher: No, the wire of the light bulb that Bear just installed was bitten by a mouse. When the wire is broken, the light bulb won't light up again. What material can be used to help the energized light bulb rekindle?
2. Introduce the operating materials to arouse children's guesses.
3, children's experiments, teacher guidance.
4. concentrate on communication.
Fourth, the end of the activity
Remind children to pay attention to the safety of electricity use.
Teaching design of "light bulb on" in large class Part II Activity purpose:
1. During the observation and exploration activities, the conductive phenomena of circuits with light bulbs and metal materials were found.
2. Be able to explore and understand simple scientific phenomena through experiments in situations, and be willing to express their findings in their own language.
3. Fully experience "science is at hand" and generate interest in discovering, exploring and communicating in life.
4. Cultivate hands-on observation and operation ability, and master simple experimental recording methods.
5, preliminary understanding of its characteristics.
Material preparation:
1. Teaching aid: a display board (figure 1), a picture of batteries, wires, light bulbs and cups.
2. Learning tools: batteries, wires, light bulbs, cups, building blocks, keys, morning check cards, pieces of paper, etc.
Experience preparation: Have a preliminary understanding of the battery through PPT.
Activity flow:
1, lead-in: in the form of questions, stimulate interest and lead to topics.
(1) The teacher turned on the tape recorder that was not plugged in. Hey, what happened to the tape recorder today? ("The tape recorder is dead", the tape is broken. )
(2) Teachers plug in the power supply to verify the results of children's guessing.
(3) Teacher: Electricity makes the tape recorder turn. What is the use of electricity? Electricity makes electric toys move, light bulbs light up and electric fans turn. )
2. Try: Choose materials and explore the circuit of the light bulb.
(1) Teacher: The teacher has prepared some materials here. Show me the picture 1. Among so many materials, there are two materials that can make small light bulbs light up. Please look at them carefully and think about them Which two do you think? You better tell me why.
(2) Teacher: Can these two materials really make the light bulb glow? Please try it yourself.
(3) Children operate freely, and teachers observe, encourage and guide (Figure 2).
(4) Teacher: Please tell us how you make the light bulb light up. Show it on the blackboard with this picture (Figure 3).
(5) Teacher: You connect one end of the wire to the light bulb and the other end to the top or bottom of the battery. As long as the light bulb touches the other end of the battery, it will light up.
(6) Teacher: Is that right? Can this connection really make the light bulb light up? Let me try it, too?
(7) Teachers intentionally choose wires with bare wires to operate. Hey! Why didn't it open?
3. Discovery: Create a scene to discover the conductivity of metal during operation.
(1) Teacher: Your light bulbs are all on. Why didn't mine open?
(2) Teacher: "Children, you all think it's the wire, and it's also the wire. Why is this line ok and this line not? "
(3) Compare the differences between the two lines.
(4) children's comparison operation, describing the operation results, boldly expressing the causal relationship between the material and whether the light bulb is on or not.
(5) The teacher described the child's conclusion: "Children, you all think that the light bulb can glow when the wire is exposed and connected to the battery, but the wire wrapped in plastic cannot make the light bulb glow when connected to the battery. Right? (6) The teacher doubts again, so that children can further perceive the conductivity of metal in operation.
Teacher: Show me the cup. What material is it made of? (Metal) If it is connected to a battery, will the light bulb light up?
(7) children operate and find that any part of metal can conduct electricity. (Figure 4)
Teacher: Please try. What secret did you find?
(8) conjecture verification: explore again
(1) Define the operation requirements.
Teacher: "Today, the teacher also prepared many different materials for the children, including morning check cards, building blocks, pieces of paper and keys. Please guess what materials are connected to the circuit, and the light bulb is on. " Which ones are not bright? Then record your guess in the form. "
(2) Children's operation records the guessing results, and teachers observe and guide them (Figure 1).
(3) Guess the result by dividing the * * stream.
Teachers count children's guess results through different questioning methods (Figure 5).
Question 1: "How many children think the morning exam board is on the circuit, and how many children think it is not? (Teacher and children count together) How many children are active? ( 16)
Question 2: "Eight children think that the paper connection is bright on the circuit. How many children think it is not?"
Question 3: "There are 1 children who think the key is connected to the circuit. How many children think it is not bright?
(4) Children's operation, verification of guessing results, communication and discovery. (Figure 6)
4. Expansion: provide electrical appliances, observe the material of the handle, and understand the relationship between conductivity and safety.
Clear operational requirements.
The teacher provided the electrician with wire cutters, needle-nosed pliers, screwdrivers, adjustable wrench, electric knives, electric hammers, electric drills and soldering irons: "Next, let's find out where their handles are and what materials they are made of, and why? Is it made of metal? "
5. Activity expansion:
Teacher: We still have a lot of materials around us. Let's do this experiment again with our parents after we go home today to see what materials can conduct electricity and what materials can't.
Encyclopedia: It is generally believed that the electric light was invented by Thomas Edison, an American. However, if carefully researched, another American, Heinrich Gbel, invented the same principles and materials decades earlier than Edison. 180 1 year, the British chemist David electrified the platinum wire to glow. He also invented the electric candle in 18 10, which was illuminated by an arc between two carbon rods. 1854, Henry Goebbels put a carbonized bamboo filament under a vacuum glass bottle to make it glow. His invention seems to be the first incandescent lamp with practical value today. The light bulb he tested at that time could last for 400 hours, but he didn't apply for a design patent immediately.
Teaching design of "light bulb on" in large class Part III Activity objectives:
1, interested in conductive phenomenon, like to cooperate with peers to explore ways to make light bulbs shine.
2. Explore the method of connecting the battery with wires and other things to make the light bulb glow, initially perceive that metal objects can conduct electricity, and boldly express their operation process and results in complete language.
3. Improve the ability of cooperative exploration and symbol expression; Understand the safety of electricity use in daily life and improve the awareness of self-protection.
Activity preparation:
1, experience preparation: observed the line and structure of the class lamp; Familiar with the name and characteristics of experimental materials; Have a preliminary understanding of the characteristics of batteries and wires; Practice cooperative routines in pairs.
2, material preparation: learning tools: the first time-two people a plate of materials: batteries, wires (light bulbs); The second time-give two people a plate of materials: cloth, wool and plastic rope, paper clip, copper key and wire, yellow and blue recording paper, pen, etc. Teaching AIDS: a scene map of the rabbit house, a mouse toy, a power cord, a set of school tools, a guessing map, a combing map, two exhibition boards, bright icons and "√, ×" symbols.
Activity flow:
First, the topic of conversation.
(Guide children to express their opinions boldly in combination with life experience)
1, show the scene diagram to stimulate interest:
Teacher: Rabbit moved to a new home today, but it was dark in the room at night. What happened? What do you need to install electric lights?
2. Encourage children to express boldly, get a preliminary understanding of the situation and let the lights light up.
Second, explore the activity "How to make the light bulb light up".
(Guide children to cooperate in experiments, explore ways to connect wires and batteries to make light bulbs shine, and boldly exchange their own exploration process and results)
1, the teacher introduced the experimental materials:
Teacher: Today, the teacher will invite you to do an experiment. The teacher has prepared a battery and wires wrapped around the light bulb for you. Think about it. How do you make the light bulb light?
2, the teacher introduced the experimental operation steps and methods:
(1) two people with one plate of materials, please cooperate with the experiment;
(2) After finishing the experiment, tell the children next to you if your light bulb is on? How did you do that?
(3) After hearing the piano, put away the information and immediately return to your seat.
3. Children independently carry out experimental inquiry activities and exchange their own experimental processes and results;
(1) The teacher focuses on guiding the children to do experiments in pairs, and does not dispute the materials;
(2) Guide children to observe the characteristics of the positive and negative poles of the battery, and encourage children to describe the observation process and results completely in language;
(3) Encourage children to exchange their experimental process and results with each other.
4. Concentrate on communication and summarize.
(1) Teacher: Let's listen together. How did these children successfully light the light bulb?
(2) Encourage children to express boldly by combing pictures.
(3) carding summary: press the light bulb connected to the lead at one end of the battery, and press the lead at the other end of the battery to turn on the electricity, and the small light bulb will light up.
(4) Connect the wires to the rabbit's house.
Third, the "connection" of inquiry activities.
(Guide children to explore the conductive phenomenon of objects independently, initially perceive that metal objects can conduct electricity, and encourage children to express the operation process and results in complete language)
1, set the problem scenario
Teacher: No, the wire just installed in the rabbit's house was chewed off by a mouse, and the light didn't work. What material can be used to connect this wire?
2. The teacher introduces the experimental operation materials, and the children guess.
(1) Doubt: Red cloth strips, green wool, white plastic rope, paper clips, copper keys, iron wires, can these things be connected by wires to conduct electricity?
(2) The teacher makes a guess on the record sheet.
3, explain the experiment and observation requirements
(1) Two children choose a plate of materials on the table to do the experiment. Each plate has two pieces of recording paper, one yellow and one blue. See what materials are drawn on it, and then do experiments according to the recorded single-choice materials.
(2) Please connect one end of these materials with the thread of the bulb-free end, and then connect the other end of the materials to one end of the battery for experiment;
(3) Every time you finish the experiment, record the results on a recording paper and write down the numbers of the two of you;
(4) After all the experiments, go back to your position and talk to the children in other groups. What materials did you use? How did you do that? What did you find?
(5) When cleaning, please stick the recording paper on the board according to the bright and unlit symbols.
4, children's experiments, teacher guidance
(1) Remind children to take corresponding materials for experiments according to the recording paper;
(2) Encourage children to do experiments in pairs, one with batteries and the other with wires;
(3) Remind children to wrap one end of the material with a wire at the end without a light bulb, and connect the other end of the material with one end of the battery for experiments;
(4) Encourage children to express the observation process and results in a more complete language.
5. Communicate in pairs.
6, centralized communication, guide children to look at the record form analysis and verification:
Encourage children to describe the experimental process and results boldly and coherently, and verify them according to their records and guesses, so as to further guide children to understand the method of lighting the light bulb.
7. Teachers and children summarize together.
Metal things like iron and copper can conduct electricity, but plastics, cloth and wool can't.
Fourth, the activity is over.
(Educate children to pay attention to the safety of electricity use)
1. Connect the wire and light the bulb.
2. Educate children to use electricity safely.
Activity expansion:
Ask open questions to stimulate children's desire to continue exploring experiments.
Teacher: What else can conduct electricity and what can't? We can go home and talk to our parents and have a try.