Observational essay for elementary school students about a small experiment .

I love insects, and whenever I have time, I go outside to observe them. Today, I did all my homework. Just as I was going outside to observe the insects, the darkness of the night began to fall, and God began to "shed tears"!

I looked at the sky and sighed, thinking to myself: the weather was fine just now, it didn't rain in the morning, it didn't rain in the evening, and it started to rain as soon as I was going out. When I was worried, my mother asked me to drink goji berry tea, and as soon as I saw goji berry tea, I immediately became interested in it.

Because I saw a lot of goji berries floating on the teacup, and there were also a few goji berries at the bottom of the teacup, I thought it was very strange. Why do some goji berries float on the water and some sink under the teacup? I thought about it carefully

It may be that the goji berries are like leather balls, and there is air in them to float on the water.

I started doing little experiments. First of all, I took out two wolfberries from the floating water, put one of them in the water, and flattened it with a pair of chopsticks. Then I took off the chopsticks and observed whether the wolfberry would sink, only to see that the wolfberry was slowly sinking.

Then I put another goji berry on the bottom of the teacup with chopsticks, and then I removed the chopsticks, and the goji berry slowly floated up and finally came to the surface of the water. Alas, I finally figured things out. It turns out that my speculation was correct.

Because the air inside the first goji berry came out, it sank. And the second wolfberry still has air in it, so it floats up.

Through this small experiment, I learned a truth, wolfberries are like leather balls, they can float on water if there is air in them, and they will sink if there is no air.

An interesting experiment.

Volcanic eruptions", you must have seen it on TV, but have you ever seen it with your own eyes? I've seen a "volcanic eruption" once, but this is a "volcanic eruption" simulation experiment, and I did this experiment myself. Hey, "volcanic eruptions" are fun.

You can also contribute.

I was asked to bring a glass, a bottle of vinegar and a bottle of detergent, a packet of baking soda, and a newspaper. Start by pouring some baking soda into the cup, then pour in some detergent, and then put the newspaper under the glass.

The experiment was about to begin, I poured some vinegar into the cup, and the miracle soon happened, just now the bottle was just some baking soda and detergent, how could it be that it only took a few seconds to turn into foam? And it was just a little bit of foam, but now it continues to rise wildly, and after only a dozen seconds, it swarms up from the mouth of the glass, overflowing the mouth of the bottle and flowing onto the newspaper. At this point, I was excited and surprised, staring intently at the bubbles that floated up, for fear of missing any details.

After about 18 minutes, the bubble gradually disappeared again. Ha, this experiment is so fun and so interesting!

Why is that? I hurriedly grabbed the book and checked it, but there was not a word on the book, alas! I had no choice but to figure it out on my own.

Didn't Mr. Liu say in class: baking soda and vinegar will have a chemical reaction to produce a lot of foam, just like soda, shaking it will also produce some foam. So what does detergent do?

I couldn't figure it out even if I racked my brain.

In order to understand the mystery, I redid this experiment again and found that the reason why foam is crazy is because detergent plays a catalytic role. Isn't this similar to the principle of formation of pumice? This little experiment is really interesting.

Doing a small science experiment allowed me to understand the scientific principles while playing, and also exercised my ability to use my hands and brains, which is really the best of both worlds.

Effect of rare earths on flowering period of flowering plants.

Shanghai Baoshan District Haibin No. 2 Middle School, Zhang Leijing, Wu Jun, etc.

With the improvement of people's living standards, people's demand for flowers has also increased. The flowers are colorful and pleasantly fragrant, but they all have the defect of not having a long flowering period. In order to prolong the shelf life of flowers, people have used many reagents, such as aspirin.

We try to use rare earths to prolong the flowering period of plants.

Rare earths are a class of rare elements. Agricultural rare earths are mainly compounds of lanthanum and cerium. It has a certain promoting effect on plant growth. To find out if it affects the flowering period and flower size, we did the following experiments.

1. Experimental materials.

Nongle powder (a rare earth fertilizer), calendula, beaker.

2. Experimental process and records: Nongle was prepared into 5 solutions of different concentrations, calendula flowers were inserted, and a control group was set up. The list is as follows: the flower diameter is 3-4 cm

Nongle Solution Situation Record.

Control 50mg 100ml

The flowers are in full bloom and wither after 1 week.

Spend 6 days after thanks.

100mg/100ml

The flowers have just bloomed, and after 2 weeks, the flowers are in full bloom.

was slightly larger than the control group.

Spend 6 days after thanks.

150mg／100ml

The flowers are in full bloom and wither after more than 1 week, and the leaves are of good color.

After 6 days of flowering, the leaves on the branches are worse than before.

200mg／100ml

The flowers are in full bloom and wither after more than 1 week, and the leaves are of good color.

After 6 days of flowering, the leaves on the branches are worse than before.

300mg／l00ml

The flowers are in full bloom and wither after more than 1 week, and the leaves are of good color.

After 6 days of flowering, the leaves on the branches are worse than before.

Eggs will sink when you put them in plain water, and they will float when you put them in water with a certain amount of salt.

Drop litmus reagent in the acidic solution, the solution is red, drop a certain amount of alkaline solution, and the red color disappears. Excessive drops, blue color.

2 points for tretretrt, 2 points for the tretretrt, and 20 points for the reward. Points Rules.

The word count should be less than 10,000 words.

1. Before, I once saw an interesting science experiment in a science magazine: the bottle "swallows" eggs. This experiment is very novel and fun.

The day before yesterday, the teacher left an assignment for a small experiment, so I decided to try it myself. I immediately looked for the materials to experiment with: an egg that my mother had boiled in the morning, a jar, a pack of matches, and a piece of paper.

2. At the beginning of the experiment, I asked my grandfather to help me draw a match, I lit the paper and quickly put the paper into the jar, and then stuck the chicken brother leaky egg with the small head down tightly at the mouth of the bottle, and stuffed the bottle mouth tightly. Suddenly, wisps of white smoke like smoke, mist, and dust in the bottle flooded the entire bottle. It's too late, it's fast, just listen to the "bang", and a miracle happens:

As if by magic, the jar "swallowed" the egg at once.

3. "Wow, that's amazing! I clapped my hands with joy and exclaimed, "My experiment was successful!" "Do you know why the mouth of the bottle is so small, and how the egg can fall into the bottle in an instant?

That's because the atmospheric pressure inside and outside the bottle is equal, the bottle mouth is smaller than the egg, so the egg is fixed, when the lit paper is put into the bottle, and the bottle mouth is blocked tightly with the egg, the outside air can not enter, and the combustion of the paper consumes the oxygen in the bottle, so that the air pressure in the bottle is reduced, so the outside air pressure is greater than the air pressure in the bottle, and the egg is pressed into the bottle under the action of air pressure.

4. This experiment made me understand that there is knowledge everywhere in life, as long as we are good at observation, and then we can gain new knowledge by practice. What a fun experiment!