In a science class, the teacher asked us to do a wonderful little experiment-to hold water on paper.

In science class, the teacher briefly talked about the experimental method, and then let's start the experiment. When the students in front finished their experiments, it was my turn. I went to the podium, turned on the tap first, and carefully filled the cup with water. Then I picked up a piece of paper, put it on the cup, pretended to suck, pressed the paper hard, and quickly turned the cup upside down. Guess what? The paper was completely sucked away by the cup, and there was not a drop of water in the cup. I was puzzled. How is this paper adsorbed on the cup? Why didn't the water in the cup come out? It really made me a monk-I couldn't figure it out, I thought: Is it a ghost? Or is gravity helping paper? I asked the science teacher with a full head of question marks. Ah! It turned out to be so amazing! It turns out that atmospheric pressure is at work. The surface tension of the water in the cup makes the paper and the cup completely closed, so the pressure of the water in the cup is less than the atmospheric pressure outside the cup, so that the atmospheric pressure firmly fixes the paper on the cup, and the water in the cup will naturally not flow out. "I see, how nice!" I suddenly realized. I think: I must do more experiments like this in the future to enrich my extracurricular knowledge.

It can be said that the world is full of miracles, and there are many mysteries waiting for us to discover, explore and study, so that we can learn more.

After reading Madame Curie's biography, I was very interested in scientific experiments, so I pestered my mother to let her take me to do it. Mother agreed, but made a request-think about it after finishing the experiment. This is no problem!

Mother brought a cup with water and a piece of white paper. I am excited to follow, always curious to ask! Mother said, "The experiment we did was called' God Paper'. Later, you have to think about why the paper won't fall. " Mother first poured half a glass of water into the cup, then pressed the paper on the bottle mouth, and then slowly inverted the cup, still pressing the white paper with her hands. Soon, the water drops soaked the paper drop by drop, and my mother asked me to let go of the hand that pressed the white paper. I was a little worried, so I let go of four fingers first. Huh? The paper is not open! I let go of my whole palm and stared at the paper, my heart hanging in my throat, thinking: don't drop it, don't drop it, don't drop it. That piece of paper seemed to understand what I said and stuck firmly to the cup! But I'm still on tenterhooks. If it falls, I don't know when it will fail. Ten minutes passed, fifteen minutes passed ... until my arm was sore and the paper didn't drop! "I succeeded!" I shouted happily.

3. How to write a big country in the composition "Big Country"

My mother was watching TV when I was eating this afternoon. She suddenly said on a whim, "Yiyi, will mom come and do the experiment with you?" On hearing the word "experiment", I was also excited. I quickly applauded. I jumped more than three feet!

"First of all, I will tell you the name of the experiment. It's called the power of chopsticks. We need to prepare: a plastic cup, a rice cup and a bamboo chopsticks. You go to find the materials. " It seems that the commander's mother spoke. As soon as I heard that there were bamboo chopsticks in the material, I thought, this experiment will definitely not be done! I hurried to get the materials, and then my mother said, "This experiment has four steps: 1: put rice in a plastic cup; 2. Press the rice in the cup by hand; 3: Hold the rice by hand and insert chopsticks between your fingers; 4: Hold chopsticks with both hands, and then lift the cup and rice together. How is it, awesome? " Mom kept her word, so the experiment was completed in less than five minutes. My mouth is so surprised that it can hold a huge "double yellow egg".

My mother looked at me completely speechless at this moment, patted my little head and said, "silly goose, this is the principle of air!" " ""air? "I asked doubtfully." Yes, it is air. Think about it: because the air in the cup is squeezed by rice grains, the air in the cup is squeezed out, and the pressure outside the cup is greater than the pressure inside the cup, which shows that chopsticks are closely connected with rice grains, so chopsticks can hold the rice grains in the cup. You got it? ""oh, so that's it! " I cancelled my surprise and put on a puzzled expression.

Through this experiment, I understand: there is science everywhere in life! Only when you care can you find them! Even the ordinary chopsticks around us have such a mystery, so what about other things?

4. Very simple scientific experiments should be explained. In the sixth grade, I wanted to write a composition about the magical power of chopsticks: insert a chopstick into a cup filled with rice, and then lift it. Can chopsticks lift rice and cups? Materials: a plastic cup, a rice cup and a bamboo chopstick. Operation: 1. Fill the plastic cup with rice.

2. Press the rice in the cup by hand. 3. Hold the rice with your hands and put chopsticks between your fingers.

4. Gently lift chopsticks with your hands, and the cup and rice are lifted together. Description: Due to the extrusion between rice grains in the cup, the air in the cup is squeezed out, and the pressure outside the cup is greater than the pressure inside the cup, so that chopsticks and rice grains are closely combined, so chopsticks can lift the cup into rice.

Reflections on the bottle race: two bottles of the same weight, sand and water, roll down from a height, who will reach the finish line first? Materials: two bottles of the same size and weight, sand, water, a rectangular board and two thick books. Operation: 1. Make a slope with a rectangular board and two books. 2. Pour water into another bottle and sand into the bottle. 3. Put two bottles on the board and let them roll down at the same starting height. The bottle filled with water reaches the finish line earlier than the bottle filled with sand. Creation: change the substances in the bottle and let them compete! Thoughts on electrified newspapers: without glue, tape and other things, newspapers can stick to the wall and will not fall off.

Do you know why? Material: 1 pencil; 1 newspaper. Step: 1. Spread the newspaper out and lay it flat on the wall.

2. After a few quick rubs on the newspaper with one side of the pencil, the newspaper won't fall off just like sticking to the wall. 3. Lift a corner of the newspaper, and then let go, and the lifted corner will be sucked back by the wall.

Take the newspaper off the wall slowly and pay attention to the static sound. Description: 1. Rubbing a pencil charges the newspaper.

2. The charged newspaper was sucked to the wall. When the indoor air is dry (especially in winter), if you take down the newspaper from the wall, you will hear the crackle of static electricity.

Creation: Please try it. What else can be stuck to the wall by static electricity without glue? Thoughts on the separation of pepper and salt: I accidentally mixed the kitchen seasoning: pepper and salt. How can I separate them? Ingredients: pepper, salt, plastic spoon, small dish operation: 1 Mix the salt and pepper together. 2. Stir well with chopsticks.

3. Rub the plastic spoon on the clothes and put it on the salt and pepper. 4. Pepper sticks to the spoon first.

5. Move the plastic spoon down slightly. 6. After salt, stick it on the spoon.

Description: Pepper is electrostatically adsorbed earlier than salt because its weight is lighter than salt. Creation: Can you separate other mixed raw materials in this way? Reflections on charged balloons: When will two balloons attract each other and when will they repel each other? Material: 2 inflatable balloons, 1 string, 1 cardboard. Operation: 1 Inflate two balloons separately and tie a knot in your mouth.

Connect two balloons with a thread. Rub the balloon on your hair (or sweater).

Lift the middle part of the rope and the two balloons will separate immediately. Put the cardboard between two balloons, and the electricity on the balloons makes them attracted to the cardboard.

Description: 1 The electricity on one balloon repels the electricity on the other balloon. The electricity on the two balloons attracts them to the cardboard.

Creation: Can other small experiments be used to illustrate that balloons are charged? Lovely watermark thinking: the beautiful patterns on rice paper are not drawn, but how are they made? Material: 1 washbasin, 1-2 rice paper, 1 chopsticks, 1 cotton swab, 1 bottle of ink and water (about half a basin) Operation: 1. Pour half a basin of water into the washbasin and gently touch it with chopsticks dipped in ink. 2. Wipe the scalp with a cotton swab for two or three times.

3. Then touch the center of the ink circle and see what happens. 4. Gently cover the calligraphy paper on the water, and then pick it up slowly. What patterns are printed on the paper? Explanation: 1 When the cotton swab touches, the ink will expand into an irregular circular pattern.

2. A small amount of oil on the scalp rubbed by cotton swabs will affect the mutual pulling force of water molecules. 3. The watermark will present irregular concentric circles.

Creation: Try other methods to change the ink pattern on the water surface. Think about the intermittent water flow: why do many streams of water become one when you touch them with your hand? Material: a tin box, awl, water operation: 1. Drill five holes in the bottom of the empty tin can box with nails (the spacing between the holes is only about 5 mm).

2. Fill the water tank with water, and five streams of water flow out from five small holes. Twist these streams together with your thumb and forefinger.

When the hand is removed, the five streams of water will merge into one. If you wipe the small hole in the jar with your hand again, the water will become five strands again.

Description: The surface tension of water separates and closes the water flow. Reflections on floating needles: Why do needles float on the water? Materials: a bowl of water, needles, liquid cleaner Operation: 1. Pour a glass of water into the cup. 2. Carefully put a needle on the water with a needle. 2. Take out the needle slowly, and it will float on the water. Drop a drop of detergent into the water and the needle will sink. Explanation: 1

Surface tension is the cohesive connection formed by water molecules. This cohesive connection is due to the fact that some molecules are attracted together and the molecules squeeze each other to form films.

This kind of film is called surface tension, which can hold the object that should sink. 2, detergent reduces the surface tension, the needle will not float.

Attention: The needle is dangerous, please ask parents to help you operate it.

Write an experimental composition on a piece of dancing paper. In college, I was deeply impressed by a philosophy class, which is still fresh in my memory. It was the day after the mid-term exam, and a classmate in the class was worried and listless in philosophy class because he did badly in all his subjects.

This anomaly caught the attention of the philosophy professor, who called him up from his seat and asked him to answer questions. The professor picked up a ... in college, a philosophy class left a deep impression on me, which is still fresh in my memory. It was the day after the mid-term exam, and a classmate in the class was worried and listless in philosophy class because of his poor grades in all subjects. His abnormality caught the attention of the philosophy professor, who took him away from his seat.

Perhaps flustered or absent-minded, this classmate paused for a moment, and it took a long time to answer: throwing it on the ground becomes a piece of waste paper, and this is its fate. The professor was obviously dissatisfied with his answer. The professor stepped on the paper again in front of everyone, and footprints covered with dust and dirt were printed on the paper. Then, the professor asked the students to answer how many fates this paper has.

Now this paper is really waste paper, what's the use? This classmate said listlessly.

The professor didn't speak. He picked up the paper, tore it in half and threw it on the ground. Then, he calmly asked the classmate to answer the same question again. We were confused by the professor's behavior and didn't know what he was going to say. This classmate is also very confused. He blushed and replied, this time it's a piece of waste paper.

The professor quietly picked up the torn paper, and soon drew a galloping horse on it, and the footprints he just stepped on just turned into vilen under the horseshoe. This horse is full of fortitude, firmness and tension, which makes people daydream. Finally,

The professor held up the picture and asked his classmates: Now please answer, what is the fate of this paper?

The classmate's face lit up and answered neatly: You gave hope to a piece of waste paper and made it valuable. The professor smiled on his face. Soon, he took out his lighter and lit the picture. In a blink of an eye, the paper turned to ashes.

Finally, the professor said: everyone saw it. A piece of paper that is humble at first, if we look at it with a negative attitude, will make it worthless. If we let paper suffer more bad luck, its value will be less. If we give up hope and destroy it completely, obviously, it can't have any aesthetic feeling and value at all, but if we treat it with a positive attitude and give it some hope and strength, a piece of paper will come back to life. A piece of paper is like this, and so is a person. A piece of paper can be turned into waste paper and thrown on the ground, trampled by us, painted and written by us, and even folded into a paper plane, flying high, let us look up. A piece of paper still has a lot of fate, not to mention us? Fate is like a palm print, winding, but no matter how it changes, it will always be in our own hands.

As for the composition, of course, it is better to do it yourself. It should be possible to write according to the material.

6. Composition of Small Experiment 120 Words In a science class, the teacher asked us to do a wonderful small experiment-to hold water on paper.

In science class, the teacher briefly talked about the experimental method, and then let's start the experiment. When the students in front finished their experiments, it was my turn. I walked to the podium, turned on the tap first, and carefully filled the cup with water. Then I picked up a piece of paper, put it on the cup, pretended to suck, pressed the paper hard, and quickly turned the cup upside down. Guess what? The paper was completely sucked away by the cup, and there was not a drop of water in the cup. I was puzzled. How is this paper adsorbed on the cup? Why didn't the water in the cup come out? It really made me a monk-I couldn't figure it out, I thought: Is it a ghost? Or is gravity helping paper? I asked the science teacher with a full head of question marks. Ah! It turned out to be so amazing! It turns out that atmospheric pressure is at work. The surface tension of the water in the cup makes the paper and the cup completely closed, so the pressure of the water in the cup is less than the atmospheric pressure outside the cup, so that the atmospheric pressure firmly fixes the paper on the cup, and the water in the cup will naturally not flow out. "I see, how nice!" I suddenly realized. I think: I must do more experiments like this in the future to enrich my extracurricular knowledge.

It can be said that the world is full of miracles, and there are many mysteries waiting for us to discover, explore and study, so that we can learn more.

7. Writing science and doing small experiments, these two words sound far away from us. In fact, it's all around us. Now I'm going to tell you about my little science experiment.

One morning, I cooked noodles at home. Later I wanted to make a poached egg as a side dish. I took out a fresh egg from the refrigerator. I looked at the egg and thought, how fragile is the egg? It will break with a light knock. At this time, I suddenly wanted to try to crush the egg, so I took the egg in one hand and tried my best, "Yi Yi Ya!" I gritted my teeth, huh? What's going on here? How do eggs go bad? I tried to pinch eggs again and again. "Alas," I finally failed. I'm out of breath. Two big greetings popped up in my heart: why can eggs bear such great pressure? Why do eggs break easily when they hit one place?

Later, I Baidu, oh! It turns out that the structure of the eggshell is round, so when a person pinches it with one hand, the strength of the hand slowly spreads on the eggshell, so that each part can bear a little pressure. For example, it will be difficult for one person to move a big stone, but it will be easy if many people move it together. The reason why an egg breaks when it hits a place is because you use a lot of force where it hits, and the hit part suddenly bears a heavy pressure, so there is no time to unfold it, so the egg is easy to break! Knowing the reason, I was as happy as if I had eaten it.

Science is everywhere, as long as you observe it carefully and be good at thinking, you will find it!

8. The ruler absorbs scraps of paper. 400 words This afternoon, in the composition class of a young reporter, the teacher asked us to do an experiment: the pen absorbs paper.

The students discussed in a low voice below: "I have done this experiment, which is simple." I saw them take out a piece of paper, tear it into small pieces, wipe it on their heads with a pen a few times and put the pen close to the paper. I looked at it with my eyes wide open, and there was no response at all. He wondered, "What's the matter? Why can't you suck it up? " He did it again and again, but he couldn't get it. I also took a piece of paper, tore it into pieces and rubbed it on my head with a pen several times, but there was no response. I'm worried. The teacher came over and saw that I was unsuccessful, so he said to me, "You need a ruler or a plastic pen to succeed." I suddenly realized.

I took a ruler out of the pencil case and rubbed it on my head a few times to keep it at a distance of 1 cm from the paper. Suddenly, the paper was sucked up. I feel that the ruler seems to have magic. In fact, it has no magic at all, it is the result of friction and electrification.

Through this experiment, I enriched my life, broadened my horizons, increased my knowledge and brought me happiness.

9. An experimental composition about the durability of a piece of paper. I am just an ordinary piece of paper. It turned out that my sister, my father, my mother and my family were very happy, but this happy family was ...

"Students, what we send below is this dictation of new words." The classroom is very quiet, and more than forty students sit neatly in their seats and listen to the teacher. I'm not idle at Master Xiao Ming's desk either. My eyes stayed on more than forty dictation papers on the teacher's desk, and I was looking for my mother. Soon mother was sent back to Xiaoming's desk by the teacher. "ah! Mom ... I'm here ... "Before I finished, Xiaoming shook his head and said with a sigh," Alas ... it's more than 40 points again, and the word 10, I made six mistakes. What a shame! " After that, he grabbed his mother with his hand and threw it into the dustbin. I froze and couldn't speak for a moment. I just felt something spinning in my eyes. Xiao Li, Xiao Ming's deskmate, saw it and urged, "Xiao Ming, you can't do this. How can a piece of paper …" Xiao Li interrupted her before she finished. "Mother-in-law, you girls are really annoying. Xiaoli sighed and ignored him.

Just when I felt sorry for my mother, the classmate behind Xiaoming patted him on the shoulder. Xiao Ming seemed to understand something, so he tore off a few pieces of paper from his notebook, scribbled a few big characters, drew a few crooked symbols, and laughed while painting. He may have written some jokes or something. The classmate behind was about to answer when Xiao Ming told him, "Don't forget to tear it up after reading it." After a while, the sound of "hissing" came from behind, and my heart followed it, tugging, tugging.

I'm really afraid that one day, my sister and I will be killed. After a while, what I was worried about really happened. Xiao Ming took his sister in white out of her schoolbag, tore it into pieces, and then wrapped it in a thick bag layer by layer, handed it to the students behind, and introduced it as "playing with evil toys." It looks like there's something in it, but in fact there's nothing. At this time, my heart hurts so much that I can't breathe.

I shouted at Xiaoming desperately: "Give it back to my relatives! Return my loved ones! " But he can't hear you.

In the dead of night, I looked at the moon outside the window and thought, what is our paper for? Is our value just for coquetry, for recording jokes, or for spoofing? I remember before leaving the factory, the worker's uncle said to us, "your's life was given by human beings, so you should repay human beings. You are the carrier of human information, a document to witness history, and a warehouse to preserve spiritual wealth. " But what about now?

We came to this world with the dream of rewarding and benefiting mankind, but how are we treated? Waste at will. Someone once calculated an account: waste paper accounts for 18% of the total garbage in China. It takes 17 trees and 100 cubic meters of water to produce a ton of paper, and most of this water will be discharged as sewage. It can be seen that paper is closely related to the natural environment. Schools are big users of paper, and an ordinary middle school student uses 474 pieces of white paper a year. Based on this calculation, how many people can be saved for every 10 thousand students? Someone has calculated that a middle school with 36 classes and 40 students in each class will send 15 notices every semester and print 43,200 copies throughout the year. In fact, these notices can be conveyed orally. Well, I don't want to think about it any more. Will tomorrow be the end of my parents and sisters waiting for me?

A few days later, I was made into a propaganda slogan by the school teacher. The slogan is: "save paper, protect the earth, start with me!" " "Although my life is over, I am very happy. Isn't a small habit a big truth? Yes, save paper and protect the earth, starting with me!

10. What are some simple experiments? (I want to write a composition) Today, the science teacher assigned an assignment that I can explore with my parents. The teacher said: "the materials to be prepared are: a spoon and a pot of hot water, and then put the spoon in the hot water." The problem is: pick up the spoon after 5 minutes and see if it is all hot. Do you understand? " "I understand," the students answered loudly.

I thought to myself: it's too simple, only the end put in hot water is hot, and the other end is not. Haha, I can beat mom and dad today ... I'm so happy! I ran home as soon as school was over. When I got home, I put down my schoolbag first, then finished my homework, then began to prepare materials, and finally called my parents out of the room. I said, "The teacher asked me to do an experiment with you. The problem is: put the spoon in hot water to see if it is all hot. " Dad thought for a moment and said, "Let's make a bet, everyone will tell his own answer, and then we will do experiments to decide who is right and who is wrong." Mother said, "In my opinion, one end is hot and the other is not." I said, "I'm just like my mother." Dad said, "I think everything will be hot." I said, "To tell you the truth, the loser has 100 sit-ups." Mom and dad said in unison, "Good!"

The experiment began. Dad put the spoon in the water. I thought to myself: Dad can't win alone. He also covered 100 sit-ups, haha! Unconsciously, five minutes passed, and my mother went to get the spoon. I grabbed it and touched it, huh? The end of the spoon in hot water is the hottest. It's getting colder and colder, but it's still a little hot up there. I asked my father curiously, "What is this?" Dad proudly said, "I won, hee hee, you and mom are going to do 100 sit-ups." As for what's going on, you can find out for yourself, check the information online and ask the teacher. "

The next morning, I walked into the science teacher's office with a puzzled face. There are already many students around listening to the teacher's answer. The teacher said, "This principle can be explained in one sentence. Heat conduction always travels from one part of an object (high temperature) to another (low temperature). "

In fact, there are still many things in the kingdom of science that we need to discover and observe in order to gain more knowledge.

It's OK to change it.