Ask for the summer I understood the composition in the eighth grade

In life, everyone will surely understand the revelation, truth or principle of one thing for us. Some of them are suddenly understood, and some of them are slowly understood. I'm the same way, and today, I'm going to introduce you to a principle that I understood after an experiment

Fire extinguishers must be known to everyone, and the main tool for extinguishing fires when they catch fire. However, do you know the principle of fire extinguishing with fire extinguishers? In order to make me understand the principle better, I also did a small experiment:

First of all, the materials for the experiment are indispensable, and the materials needed are: a film box (with a lid), a bottle of vinegar, a roll of toilet paper, an iron spoon for eating and a bag of baking soda. Now that the materials are ready, let's start experimenting!

First of all, pour half a bottle of vinegar into the film box, and remember that the tested film box will no longer be able to hold film. Then, sprinkle about three tablespoons of baking soda on a piece of toilet paper, roll the baking soda in it with toilet paper, tighten the ends of the paper, and wrap it into a candy shape.

Finally, quickly place the candy-like baking soda into the film box and close the lid. After a while, the roll cap is pushed open, and a large amount of foam from the mixture of carbon dioxide gas and liquid overflows the film cartridge. But I did it all according to the method in the book, and I didn't even burst a single bubble, what happened?

My mom and I stared at each other. I thought about it for a long time, but I still didn't have a clue, and suddenly, I seemed to think of something. A slap on the thigh, eh!

It turned out that I didn't put enough baking soda, and the book said that I should put three full spoons of baking soda, but I only put one and a half spoonfuls, because I only put half a spoonful of each spoonful, no wonder I couldn't even spray a bubble.

Knowing the reason, my mother and I turned up the measurement again and put three spoonfuls of baking soda, which seems to be more successful this time. I thought to myself. Sure enough, after increasing the amount this time, a lot of bubbles and vinegar were sprayed out of the cup, so I was happy!

However, this time the squirting is far less than what is written in the book. It seems that a new problem has arisen, and when I open the cup, I am dumbfounded. It turned out that there was still a lot of baking soda in this cup that had not been wet with vinegar.

It seems that just pour a little more vinegar will do.

Finally, the third experiment was successful, and I just closed the lid for less than two seconds when I heard a "puff" sound and was pushed open, squirting out a super invincible amount of foam and vinegar, which was spectacular! After doing the experiment, I seem to understand a little bit of truth, for example, baking soda and vinegar may produce bubbles and other substances to extinguish fires. In order to prove my idea, I also quickly looked at the final principle, which is similar to what I thought:

When the paper wrapped in baking soda meets the vinegar, a chemical reaction will occur, producing a large amount of dioxide gas and foam, and the bottle cap will be opened, and the foam fire extinguisher is such a principle.

Oh, I see, I suddenly understood the principle, if there is a fire in the house, I can also use this method to extinguish the fire! Just kidding.

I got it during the summer vacation.

The colors of childhood are rich, and the innocence of innocence is innocence, and in that personal experience, I really understood a truth......

It was a hot day this summer, and I came home from playing badminton at school, already sweating profusely. I wanted to find a cup of cold water to drink, but I didn't expect that the water was boiling and hot, and I thought: Isn't this water like being fished out of a pot, hotter?

No, we have to find a way. My eyes rolled "bonely", and there were! I filled a glass with water and put it on the top level of the fridge – frozen.

I looked at the fridge and thought that my mom would come back and praise me for being a smart kid and reward me with ice cream!

Just thinking about it, I heard a "bang", and the glass shattered!

I sat on the ground crying with a "wow", thinking about how to explain to my mother that the magic energy just now had already disappeared completely......

"Mom came back, and when I saw my face full of tears, and then I looked in the refrigerator, I already knew half of it. My mother quickly helped me up, and I cried and asked my mother, "Mom, why does the glass break when I put hot water in a glass and then put it in the refrigerator?"

When my mother saw me like this, she smiled and said to me, "Haha, don't you understand the truth of 'hot expansion and cold contraction'?" This is the use of the principle of 'thermal expansion and cold contraction'.

If you think about it, the water in the glass is hot, and the cold air comes out of the refrigerator. ”

Through this personal experience during the summer vacation, I understood the truth of "hot expansion and cold contraction", and I will not make this mistake again in the future!

An unforgettable moment.

Every time I think of an unforgettable moment, I always remember it, it always lingers in my heart, and it will never linger in my heart. In this lingering moment, sometimes it is self-helping, and sometimes it is also used to help others and warm people's hearts. Lead me to a better future and serve me for the rest of my life.

I remember it was a dark day, the sky was not as clear as it used to be, and it became lifeless, as if something was going to happen. At this time, suddenly from the bridge in the distance, a figure riding fast appeared, hurriedly riding down the bridge deck. Then suddenly there was a flash of lightning, followed by a rumbling thunder, and his face turned pale with fright, his body trembled, and then he did not know what was wrong.

I saw him rush into a big puddle, turn the front of the car, rush to the green belt, and fell into the wet mud, I don't know what is going on outside, only that he is lying in the mud.

This little boy is - me.

At that time, I only knew that it was going to rain in the sky, and I was in a hurry to go home, but who knew that a thunder scared me into a cold sweat, and I was also anxious to cover the rain, so I didn't see the front clearly, and I fell into the mud, and there were bursts of pain on my body.

I don't know how long it took, the rain was getting heavier and heavier, like a downpour, I was woken up by this downpour-like cool rain, my eyes were blurry, I felt that the clothes on my body had been soaked by the rain, and my feet had been numb, as if I had lost consciousness, and my body was full of injuries, which can be described in one word - "scarred". Helpless, I opened my eyes and thought, "Somebody can help me?"

I opened my eyes with great effort, and dimly saw a figure, hunched over, as if he was also hiding from the rain, holding a cane in one hand, holding a newspaper to cover the rain, slowly and leisurely walking towards me. He walked into some, he was a gray-haired old man, dressed plainly, and there was a bit of opulence in it. Closer I saw that his face was wrinkled, but he was very kind and kind.

When he saw me, he immediately quickened his pace, stretched out his hand and pulled me up, his hand was very warm, which warmed my heart, and he said kindly: "Xiao Crack pretends to be a friend, are you okay?" I nodded, my heart already filled with a warmth, even though my body was still cold.

He said, "Little friend, where is your home, do you want to go with you?" I shook my head and said

Thanks, no need, I'm fine! Then the old man took out a crumpled paper towel and wiped the water and dirt on me. He disappeared at a turning foot full of love and warmth.

Although there are only a few warm and kind words; Although there are only a few amiable movements; Although there was only a crumpled tissue. But that's not all. It was an unforgettable moment.

I only have this one.

In the six years of primary school career, we didn't seem to understand the pain of parting when we were naïve, and the big family of 37 people "sowed discord" from time to time and had unnecessary disputes.

I remember when I was in the second grade, my table mate was a boy with a "clever mind", and his little hands could always fold many vivid little things, so I had some respect for him. However, he is a stingy guy. At the end of class that day, he was showing me his carefully folded paper airplane, and I was curious to touch the paper airplane, but the classmate got angry and stretched out his dexterous hand to grab ...... in my faceMaybe it was a momentary impulse, maybe there were still four years left, and I was too young to know how to cherish it!

But, strange to say, we have been friends ever since.

In elementary school, we were very playful, chasing and fighting in the hallways, and bumping and bumping in the classrooms. I often hide from my teachers and parents to go to the small shop at the door to buy a bun of dry noodles and buy a barbecue to try, and for some reason I always feel that these things are delicious ......

We were very happy at that time, and we never thought about what to do after we were separated. Until one day ......

At the sixth grade's celebration of June 1st, it seemed to be the death day of our class. Our homeroom teacher asked each of us to say a word to our classmates and teachers. The six-year friendship has only been revealed today, and every student has spoken the truth in their hearts.

Listening, listening, for some reason, my heart suddenly soured, and tears flowed. Almost everyone in our class cried that day. Yes, how can a six-year friendship be broken just as soon as it is broken?

In elementary school, it is the bridge from naivety to maturity, friendship, this thing is also at this time, our friendship, so like the foundation, is firmly laid, no one wants to destroy! Our homeroom teacher, who has been teaching us for three years, tutored us wholeheartedly, and taught her last class of students, naturally, the friendship with us is also very deep, and she is kind and kind, regardless of her face, she shed clean tears......

Six years of friendship, overnight farewell. At this moment, I finally understand that friendship needs to be cherished!