Operational difficulty: ★★
Experimental method:
Take a ripe apple, insert a copper wire and a knife into the apple 2-3 cm deep, keep the copper wire and the knife about 1cm apart without touching them.
Connect one end of the earphone wire to the copper wire, and the other end is in intermittent contact with the knife, and you will hear a “click” from the earphone.
Take down the earphones, connect the other two wires to the copper wire and the knife, then place the other ends on your tongue, but don't let them touch each other. At that time your language will be strange. All this proves that the current generated by Apple passes through the headphones and your tongue.
Replace apples with tomatoes and lemons, repeat the experiment above and you will find that they can all produce electric current.
You might say: "With such a small current, even smallThe electric beads can't light up, it's not exciting." Well, let's make a big battery and light up the small electric beads.
Take 12 larger potatoes, 12 leaves of zinc and 12 copper sheets Zinc sheets can be cut from the outer skin of old batteries. If there is no copper sheet, a thin copper wire can be wrapped tightly around the small piece of wood. If the copper wire is enameled wire, the paint should be scraped off. Insert a piece of zinc and a piece of copper spaced 1 cm apart. Then use wires to connect the copper piece. potato to the zinc piece of the other potato
Now connect the head and tail connectors to the small 1.5 volt electrical bead And there you have it, the small electrical bead. lights up.
Extension of knowledge:
In fact, not only fruits and vegetables.can produce electricity, but also the difference between hot and cold temperatures can produce electricity. Take two thicker copper wires and an iron wire about 30 cm long. Scrape the insulating paint on both ends of each copper wire, then firmly connect the two ends of the iron wire with one end of the two copper wires. Use wires to connect the other ends of the two copper wires to the two terminals of the sensitive galvanometer.
Now put a joint of the wire into the beaker filled with the ice-water mixture and hold it low; place the other joint over the flame of the alcohol lamp to heat it to a very high temperature. At this time, the galvanometer needle deviated significantly, indicating that a current was being generated in the circuit.
This phenomenon has aroused great interest among scientists. Further experiments proved that the size of the current generated est related to the properties of the two connected metals and the temperature difference between the two connection points. This phenomenon was therefore quickly used to measure temperature and made it possible to manufacture an extremely sensitive thermometer. Scientists are still studying the use of temperature differences between the ocean surface and deep layers to build thermoelectric power plants.
Interestingly, if the ammeter is replaced with a battery, the other ends of the two copper wires are connected to the two poles of the battery via wires. Then the initially hot joint will release heat and the temperature will drop; the initially cold joint will absorb heat and the temperature will increase. This phenomenon has been used by scientists to create refrigerators.
What am I? The second grade handwritten journal on the process of water change
In the study quotidienneMany people have written compositions during their studies, their work or their lives. Compositions can be divided into time-limited compositions and non-time-limited compositions according to different writing time limits. Do you know how to write a good essay? Below is the composition of the water bottle story that I carefully compiled. I hope it can help everyone.
Aquarius Story Composition 1This morning, I was thrown onto the balcony outside of classes 4 and 5 by a classmate who was in the fifth grade, and I stayed there all day.
After the first lesson, the students of classes 4 and 5 rushed outside. Some went to the bathroom, some carried their homework, and some played. After a while, a classmate kicked me. Before I could recover, another classmate gave me akick. The pain was unbearable. At that moment, I really wanted to rush up and kick them hard, but I couldn't move. Even though they kicked me, no one picked me up.
After the second class, I saw a female teacher wearing a black coat and a serious face approaching. She looked at me, paused, then left. I wondered why she didn't come get me. Is she lazy?
After the third period, no one came to pick me up, so I had to continue to lie down alone. I really want to grow up and run home, so I don't have to wait for these people who "don't have eyes".
At the end of the fourth period, the students' cheers made me very curious, what was happening? It turns out they are no longer in school. I watched them leave one by one with disappointed and angry eyes. At noon, the school was silent.
AfterBy noon, the school was very lively again and the students gathered like a market.
After the first lesson in the afternoon, the classmates in the fourth and fifth classes did not fight as much as in the morning, but there were many discussions, as if to find out why the teacher didn't choose me I know, it's not because I'm lazy, but I want to see which classmate has the brightest eyes.
After the second class, I was finally picked up by a man. He wore a neat suit. There were a few wrinkles on his smiling face. Judging by his dress, he seemed... Director. The manager leaned down gently and picked me up, then walked to the railing and looked down to see if any of my companions were there. If so, we could go home together.
I'm so sad and I really want to say loud and clear to my lovely classmatesth class: "Let's treat the school like our home and protect the environment in which everyone lives and studies; keep your eyes open, move your hands, and... Let's have a clean and beautiful campus!"
Aquarius Story Composition 2Let me tell you an interesting story
There are two thermos bottles. One is wearing a red shirt. He is the older brother, he is knowledgeable, modest. and cautious, dressed in a blue coat, is his younger brother, proud, boastful and arrogant.
One day the little master slept until midnight and got up with it. thirsty to drink water. Suddenly he heard the sound of conversation. After listening carefully, it turned out that it was two thermos bottles whispering, one was bragging. other was talking. Listen.
I only heard my brother ask: "Brother, why aren't you asleep yet?" The younger brother said: "I'm so excited. I got 100." extra points tomy math test today. the whole class and the teacher congratulated me. "You are the best." The older brother said, "Brother, you are great!" The younger brother continued, "Of course, there is no doubt that can surprise me. I am invincible." the older brother listened to his younger brother's words, he asked his younger brother a question. “Why wouldn’t a thermos bottle filled with boiling water fly, but the cap from a bottle not filled with boiling water would fly?” The younger brother thought for a long time, but could not answer. The eldest brother explained: “The bottle cap that flew off was pushed up by the hot air. » After hearing his explanation, the younger brother blushed, lowered his head and shed tears. The older brother saw that his younger brother knew he was wrong and smiled happily, because he felt that he had helped his younger brother correct his faults.
This story tells us a verity, a person should not be proud of their achievements. You must know that the strongest has his own strong hand and that each mountain is higher than the other!
Aquarius Story Composition 3Once upon a time there was a beautiful stationery family, whose members were: an inkwell, a pencil, a pen, a ruler... They played together every day, and they were so happy !
One day they all received invitations to Pen's birthday party and they spent the whole morning getting dressed at home. The birthday cake ordered by Inkpot arrived at noon and he had to sign for express delivery. As he walked on the way to sign for the express delivery, the ink bottle smelled a burning smell, which seemed to come from the pencil's house. He wanted to know what was going on, but the ink bottle followed the smell and found the source of the fire without bothering to sign for express delivery. Thick smokeescapes from the pencil house. The pencil maker is made of wood, what should I do? He really couldn't find a good way. He rushed forward despite the danger and threw the ink he had brought into the sea of fire. He put out the fire and saved the pencil. Unexpectedly, the pencil didn't thank himself, and said angrily: "You soaked my dress." when I went to the pen. "How can I attend the birthday party?" After hearing this, the inkwell bowed his head and left silently. He also didn't sign for the gift.
In the evening, Pen held pieces of birthday cakes and gave them to friends who were not there. He arrived at Pen's house as soon as he walked through the door, he said to Pen, "Why did you do it?" “You didn’t attend my birthday party?” “There must be a reason your dress got wet.” ", Pencil said angrily: "There was a fire in my house and the bottle of ink used"Fountain Pen smiled and said, "I'm saving you out of kindness. If you don't wet your clothes, you will be burned alive. You must surrender at Inkpot tomorrow to apologize.
The next day, Pencil came to Inkpot and said sincerely to Inkpot: "I'm sorry, Inkpot smiled and said: "It's okay then. world had another birthday party for the pen The pens and the ink bottles get together, in a big wayThe family had so much fun
Composition 4 from the story of AquariusA bottle! water and the water in it are a pair of good friends who are inseparable. Water scrapes the water bottle every day, and the water bottle benefits every day.
However, the good times did not last long. One day, the owner wanted to take the water bottle to clean it. When he took it, the owner accidentally saw it.dice water from the water bottle. At first, Aquarius did not realize that his good friend had left him. Later, Aquarius felt that his body was itching more and more.
I was still asleep when the water from the water bottle was poured. In my dream, I felt like I was riding an unsteady roller coaster. When he woke up, he found himself in a cove. The water in this stream is very clear, and the water from the water bottle has made many companions here.
Shui asked the companion next to him: “Where does this stream lead? » The companion replied: “This stream leads to a large reservoir, and there is a place further on. »
Shui and his companions arrived at a large reservoir. They saw a filter guarding a large water pipe on the side. Shui curiously walked to the filter and asked, "Is this road accessible?" » The filter replied: "Go to the water plant, then filter and disinfect the water beforeto send it to thousands of homes in the city."
The water asked again: "Is there any other way?" The filter pointed to the other side and said: “There is a hydroelectric power station under the reservoir dam there. You can also get out of there. "The water thanked the filter and went straight to the power plant.
The water rushed down from the heights with many of its friends, causing the turbine generator to spin with a roar, and soon it gushes out of the water outlet at the bottom of the dam. There is a sign at the outlet: "This river leads to the sea."
I don't know how many days and nights there are. flowed by the water, and I went to many places, walked and looked at them all the way, and finally came to the open sea. good friend Aquarius begins to miss Shui How can he find his friend One day he saw a ship passing by on the sea and rushed forward and asked?: “How can I return to land? " The ship said, "The only way is to let the sun evaporate you into water vapor and fly towards the water. the sky, then turned into water vapor." The raindrops fell. "
The water happily thanked the ship and remained on the sea basking in the warm sun. After a while, the water really turned into light water vapor, floating in the sky. He asked a cloud for help: "I want to return to the earth, can you lead me?"
Then the water vapor turned into small water droplets and landed on the cloud. the cloud Move it towards the earth. When we arrived at one place, the water looked familiar. Then the cloud shook his body and it really started to rain. At that time, his good friend Shuiping was outside, basking in the sun. He opened his mouth and shouted, “Why is the day changing? It suddenly started to rain.Woolen fabric? »
The small water droplet on the cloud fell, and it landed in the water bottle at a glance. The water bottle recognized the little water droplet as its good friend and said hello to it in surprise: "Hello, long time no see, you, where did it go?" said: "I crossed a clean stream, went to a reservoir with a water plant and a power plant, went to the sea and made a detour to the sky for a walk. Now I'm finally back. Aquarius said: "I really envy you. Is it fun to travel to so many places?" , I learned a lot.”
From that moment on, Shui and Aquarius lived the same carefree life as usual.
Composition of the story of Aquarius 5 < p> On the weekend, Xiaoqin's father came to visit her aunt at thehouseAfter lunch, my aunt took her father to her friend's house to repair the television. Xiaoqin thought to herself: Dad and aunt went out, and there is no one at home. I can take advantage of this time to boil water and. Wait, dad and aunt have been drinking. Xiaoqin boiled the water, picked up the teapot and wanted to pour the water into the thermos. Just as she poured the water, a puddle came out and the. water was sprinkled on Xiaoqin's feet. Xiaoqin shouted, loosened her hand, kicked it, and the thermos bottle fell, then there was a "bang" Xiaoqin thought: I broke the thermos bottle before. , but now she doesn't love me anymore! In all haste, Douda's sweat fell and the pain of the burned foot was forgotten. Finally, Xiaoqin decided to lie and took a rag to wipe off the water and clean the hot. water bottle fragments.
In the evening, I urged my father to come home quicklyat home, saying there was still homework to do, but my father said, “It’s okay, it’s still early, I’ll do it.” leave after dinner. » "After eating, although the rice was delicious and the dishes were rich and varied, Xiaoqin still had no taste. After a few mouthfuls, she stopped eating and told her father to go home quickly.< /p>
There was nothing Dad could do with Xiaoqin. I had to say goodbye to my aunt and go home. the chair and said: "Xiaoqin, what's wrong with you today Xiaoqin said hesitantly: "No...no...it's okay Dad asked in confusion." : “You must be hiding something from me! After being severely questioned by her father several times, Xiaoqin told her father the truth: “Honesty is priceless If you do this. when you are a child you will lose your integrity as you grow up, and you will lose it. not being able to gain a foothold in society. " Xiaoqin came to the phone with a red face and lowered her head and called her aunt: "Auntie, I'm sorry, I broke the iron thermos bottle. "After saying this, Xiaoqin thought that my aunt would scold me. Unexpectedly, a soft voice came from the phone: "It doesn't matter if you know it, you can change it or you will be a good child. Xiaoqin listened, danced, and shouted loudly: “Auntie, forgive me. ”
What am I? The second grade handwritten journal about the water changing process. The relevant content is as follows:
< p>Handwritten diary theme：What am I? The changing process of waterContents of the handwritten journal:
Title: In the handwritten journalAt the top, write the topic “What is the process of changing water 'water' in big letters.
2. Threestates of water: Draw three icons or illustrations to represent the three states of water: liquid water (lake water, river water), solid water (ice cubes), and gaseous water (steam clouds). ).
3. The changing process of water: Use text and illustrations in the handwritten journal to show the changing process of water between different states, for example:
Liquid water can become solid water. , when the temperature is below freezing, water freezes into ice cubes.
Solid water can turn into liquid water. When ice cubes are exposed to heat, they melt into liquid water.
Liquid water can turn into carbonated water. When water is heated, it turns into steam and forms clouds.
Soda water can turn into liquid water. When steam encounters condensation, it condenses into small water droplets.
4. Water cycle process: usesUse diagrams or illustrations to show the process of the water cycle, including evaporation, cloud formation, precipitation, surface runoff, rivers and lakes. Arrows can be used to indicate the direction of water flow.
5. Uses of water: Let students understand the uses of water in daily life, such as drinking water, bathing, agricultural irrigation, power generation and swimming.
6. Water Conservation: Emphasize the importance of water and how we should save water resources like turning off taps, fixing leaks, not wasting water, etc.
7. Interesting Water Knowledge: Add interesting water knowledge, such as water density, water color, water taste, etc.
Illustration suggestions:
Draw illustrations of liquid water, watersolid and sparkling water in bright colors.
Use dynamic arrows in illustrations to represent the changing process and the circulation process of water.
Draw a dry map, then add clouds, rivers, lakes and raindrops in various locations to show the water cycle.
When writing this handwritten report, be sure to use simple, easy-to-understand language and illustrations so that second graders can understand and enjoy it. The goal of the handwritten journal is to convey basic knowledge about water through visuals and text, while raising awareness among students about the importance and conservation of water resources.