Whether you are in school or entering society, everyone will inevitably come into contact with or use compositions. Compositions require a complete chapter structure, and you must avoid compositions without endings. How to write an essay to avoid making mistakes? Below are 7 fourth-grade science compositions that I have carefully compiled for your reference. I hope it can help friends in need. Fourth Grade Science Composition 1
Since I read "One Hundred Thousand Whys", I have learned more about science, and the big question marks in my heart have been changed into staggering exclamation points. I remember a celebrity once said: Books are the source of knowledge, we love science essay 450 words.
When I was a child, everything in the cartoons was alive, the stars could blink, the sun could brush teeth, the moon could wear clothes... I was full of questions─Why can’t I see it in reality? arrive? I saw "One Hundred Thousand Whys" "walking" over in a swaggering manner, oh! I get it, those things are just made up by people.
One day, I was overwhelmed by a lot of scientific information. Just when I was in a dilemma, "One Hundred Thousand Whys" suddenly flashed in my mind, yes! Books are our good teachers and helpful friends. Whenever I encounter difficulties, they are the ones that can help me find the answer as soon as possible. "Found it, found it." I said, I was extremely happy to find the information.
Why don’t the shining stars fall? Why is there lightning and then thunder? Why is there day and night? Why is spring warm and winter cold? The natural world is really amazing. There are many big questions waiting for us to explore...
I love science and the countless "whys". It makes me grow faster and makes me more confident. My thoughts are given wings to dreams! Fourth Grade Science Composition Part 2
On Sunday, my mother and I did an experiment together.
I followed my mother’s instructions and brought a dry empty glass, a lighter, a few candles and some lime water.
First, my mother took out a candle, lit it carefully, and held it vertically. Wax dripped onto the table. When the wax oil was not solidified, my mother glued the candle to the table. Then, my mother shined the empty cup on the side. At this time, the candle extinguished the sparks like a well-behaved child. After reading it, I felt that this experiment was not very strange, but I couldn't give any reason, so I had to ask my mother for advice.
Mom said that because the fire needs oxygen when burning, and the cup covers it, the oxygen inside is restricted, and the flame will soon burn out the oxygen. When there is no oxygen in the cup , it will go out automatically.
Next, my mother poured the clarified lime water into the beaker, rinsed it around and poured it out. A layer of lime water would be attached to the wall of the beaker. He put the beaker over the flame again. After a while, the lime water on the wall of the beaker became turbid.
"What's going on?" I was puzzled.
After hearing this, my mother laughed and said, you should go ask the computer teacher for help!
When I heard this, I turned on my computer and looked it up. It turned out that this was because the burning candle produced carbon dioxide. When limewater hits carbon dioxide, it undergoes chemical changes to form white solid calcium carbonate that is insoluble in water. "Oh, that's it!" I hurriedly called my mother and showed her the instructions on the computer. Mom laughed and said: "You have learned something new today."
What an interesting experiment! In the future, I will do more experiments and learn more about scientific knowledge! Fourth Grade Science Composition Part 3
I have a dream, I hope I can become a scientist in the future. I subscribe to many scientific exploration magazines and am also a loyal fan of "News for Truth". My wish is to invent and manufacture items that help people. Lying on the sofa, fantasizing about growing up, I slowly fell asleep.
I suddenly became an adult and came to the laboratory. Look, these are water walking shoes. I developed this based on the fine hairs on the feet of water striders. The fine hair contains an oily substance, and the density and weight of the oily substance are less than that of water, so it can glide freely on the water.
This pair of shoes uses the same principle. Whenever you want to stand on the water, the shoes will automatically stretch out a row of fine hairs on the soles, which can carry a weight of 200 kilograms. Therefore, people can not only stand on the water, but also Walk, run and jump easily and freely on the water.
The phone rang. There was a flood in the southern region and a large number of water walking shoes were needed. I immediately rushed out the required quantity overnight and quickly went to the disaster relief site early in the morning to hand over the water walking shoes to the rescue officers and soldiers. them. The rescue officers and soldiers put on the water walking shoes I made to ensure their own safety and rescued all the victims more quickly. I was very happy to see that they were all safe.
I returned to the laboratory and continued to make my new invention-the sonic gold-cutting gun. This gun was developed using the characteristic that "sound waves can shatter stones." Just adjust the sonic wave with the sonic adjuster. When in use, just turn the button and adjust the measurement to easily turn hard stones into powder. I took this gun with me to the road construction site. They were digging a cave. It was not only time-consuming and labor-intensive, but most importantly, it was very unsafe. I handed the sonic gold-cutting gun into the hands of a worker and taught him to rotate it gently. The boulder in front instantly turned into powder and floated in the sky. It was very safe. This avoided the danger of hurting people due to gunpowder and digging. . In less than half a day, the cave was filled. Everyone saved time and energy and cheered together! Before leaving, I repeatedly told the workers that they must wear earmuffs when using the equipment because the sound waves are huge. If the sound waves are too big, they will damage the eardrum and thus damage hearing.
"Ning Ning, get up and eat!" My mother's voice suddenly sounded. I opened my eyes and looked around. It turned out that this was a dream! I looked at the science magazine in my hand and secretly made up my mind. Although I am still a primary school student now, I will study hard, step by step, and strive towards this goal, and become a scientist who serves the people! Fourth Grade Science Composition Part 4
One day, I caught a little frog. I put it in a bottle and raised it carefully.
This little frog is only the size of a bottle cap, yellow in color, with brown patterns on it, and a pair of big bulging eyes, making it look like a beautiful little frog. The little frog's front feet are thin and short, but the hind feet are thick and powerful, and can jump more than ten centimeters in one jump. There are four toes on each front foot and five toes on the hind feet. The part connecting the toes is called a "web". Little frogs like to eat small live animals, such as flies, mosquitoes, moths and the like. When it is hungry, I will put everything aside and catch insects for it first.
This time I spent a lot of effort to catch a mosquito, then put the live mosquito into the bottle and quickly closed the lid. As soon as the mosquitoes got in, they kept flying, trying to get out. But after flying for a while, he stopped and took a rest. The little frog may have noticed that food was coming to the door, and immediately dived to the bottom of the bottle, motionless like a stone sculpture. The mosquito started again, slammed into the bottle cap, and stopped to rest. It went back and forth several times, and its physical strength gradually became unable to support it, and it slowly fell down. When the little frog saw that the time had come, he rushed out of the water like an arrow from the string. As soon as he stuck out his tongue, the mosquito became its delicious meal. The little frog ran to a corner and slowly enjoyed the delicious food, as if he was afraid that others would snatch his spoils. However, this small meal was too little, and I had to try to swat a few flies for it to satisfy its appetite.
The little frog is an expert at catching pests and is very funny. I have always regarded it as a good friend and it has brought me a lot of joy. Fourth Grade Science Composition Part 5
Science and technology are the primary productive forces and play an important role in the development of human history. In human life, science and technology are widely used in various fields.
In agriculture, due to the application of science and technology, humans have developed hybrid rice and genetically modified fruits. Continuously increase food production and optimize quality. Humans have also invented various kinds of planters, fertilizer spreaders, and harvesters. Less and less human labor is invested in agriculture.
In the medical field, due to the application of science and technology, people have invented a variety of high-tech medical devices and drugs, which can treat patients without any pain and extend human life. extend.
In terms of national defense, due to the application of science and technology, scientists from various countries have invented various technological weapons - missiles, fighter jets, radars, etc.
They play an important role in safeguarding the territorial integrity of the country.
In terms of life, due to the application of science and technology, we have invented telephones, televisions, computers, cars, and airplanes. It enables us to go to heaven and earth and communicate with each other thousands of miles away.
Science and technology are so amazing! Scientists are so great! Fourth Grade Science Composition Part 6
The science section on Thursday really pissed me off
"Today, we learn 'pendulum'" the science teacher made an interesting opening statement. "Oh~ Pendulum..." "Aren't you studying mechanics?" There was an explosion under the podium.
"Ahem... um. Yes, we will learn to swing today." The teacher announced the truth. The representative of our group went up to receive the experimental props - two nuts, a short rope, and a shelf (sorry, I forgot the name). We hang the rope on the hook and put the nut on the hook. Get your stopwatch ready and start timing. The rope pulled the nut and swayed, reminding me of the pirate ship in the paradise. Um. Um? Kind of hypnotized. I saw Chen Xiqi counting back and forth, his hand dangling back and forth, a bit like... "Haha, it seems like I'm slapping you." He smiled like a devil, and the fat on his face was shaking. "Boys are so annoying!" I thought. Look at the two people next to the group of four. One is playing with a pen. If we were in English class, I would have crushed him to death (I am the representative of the English department)! The other one is keeping time, yes, yes, he is my best friend, but the emergency made him not only not help me, but also stood idly by! Angry, angry, angry!
Oh~ I seem to see hope (too exaggerated), the teacher is here. I immediately turned back into a good girl and complained pitifully to the teacher: "Teacher, Chen Xiqi is hitting me (since I am the representative of the English department, my daily conversations often involve English)!" After saying that, I turned around to look at Chen Xiqi's embarrassed look. . Unexpectedly, the teacher actually said: "Chen Xiqi is a good boy, how could he hit someone?" There was a hint of ridicule in his words. "Did you hear that? The teacher said I was a good boy. Yes, yes!" So shameless! I'm almost mad! Fourth Grade Science Composition Chapter 7
Today at noon, Xiaoshan Daily’s little reporter activity - learning science magic came into the gate of our Yingfeng Primary School. Our little reporters came to the classroom on the second floor with great excitement. Everyone blinked with curious eyes, wanting to see the magic of magic and explore its secrets!
The magic of anticipation begins! In just one hour, the teacher performed ten magical magic tricks for us, including obedient eggs, lifting and lowering at your discretion, sensitive noses, coming and going without a trace, continuous cutting of ropes, vertical pencils on fingertips, relevant and irrelevant, Magic handkerchief, balloon in bottle, old rooster laying eggs. After hearing these ideas, everyone is a little confused, and I am too. Magic is about dexterity, and it also contains scientific principles, otherwise your magic will be compromised.
When the teacher needed an assistant to go up and experience the magic of "pencil standing on fingertips", we held up a "small forest" under us, and someone was lucky enough to go up and do the magic, a pencil, a pencil Wrap a wire around the upper part. It is best to hang a bunch of keys next to the wire and use the center of gravity balance principle so that a pencil will stand up steadily. You can try it. There is also a more interesting "sensitive nose". Prepare three coins, hold them in the palm of your hand, let the magician with closed eyes smell them with his nose, and put them back. The magician opens his eyes and picks up each coin and smells it. , and soon he said, "Get the coin you just took. Isn't it amazing!" Let me tell you secretly, in fact, the magician picked up the coin and touched the tip of his nose quietly, pretending to smell it. He was actually sensing the temperature, because the coin just held in the palm of his hand had the ability to absorb heat and conduct heat!
The little world of magic inspired my enthusiasm and interest. When I got home, I couldn’t wait to show it to adults who usually know everything better than us. It also made me understand that magic comes from science. and knowledge.