Science experiments in the sixth grade, hurry!!!!!!!!!!, hurry

The changes in baking soda and white vinegar, especially in this experiment, bubbled, expanded in volume, and the walls of the cup cooled (endothermic reaction).

1 c The Himalayas are plate collisions The Brahmaputra Grand Canyon is plate stretching.

2 c The appearance of water droplets on the wall of the test tube indicates that there is water in the soil The water evaporates and liquefies on the wall of the test tube at low temperatures.

3 A The temperature difference between day and night in Xinjiang is large, the temperature is high during the day, the sun is fierce, which is conducive to the synthesis of organic matter for photosynthesis, and the temperature is low at night, which inhibits respiration and reduces the decomposition of organic matter, so the organic matter accumulates more.

4 b The frontal mirror reflects light into the patient's ear for easy observation.

5 A Due to the serious soil erosion of the Loess Plateau in northern China, which affects the northern part of China, sandstorms form in the windy season.

1、c.Brahmaputra Grand Canyon.

2、c.Moisture content.

3、b.Sunlight.

4、b.Reflection of light.

5.a The northern part of the country.

The first question is that if it is stretched, it is c, and if it collides, it is b

The second question is water c

In the third question, I vaguely remember that the temperature difference between day and night is large, which causes the grapes to breathe slowly at night, so only a small amount of sugar stored in the grapes during the day is decomposed as respiration energy, so it is very sweet, so I think the third question is A

Question 4: Reflex.

Question 5a: North.

Actually, I will answer these questions for you, and I will help you answer them and say why, but you are obviously despising the poor students, and your attitude is very improper, and you are only in the fifth grade of primary school, and you are only in the fifth grade, and you despise the poor students, Nima, Darwin, and Einstein When I was a child, I was a poor student, and later achievements Can those good students be compared Please don't treat the poor students as bad at all, thank you.

Example 1 What experiments can you do with a syringe?

Analysis The syringe is not new to us, if you can use your brain, you can do a lot of experiments by using its characteristics such as "the piston can pull" and "seal a part of the gas".

Plugging the front hole with your fingers and pulling the piston outward with your other hand is very laborious, and if you stop exerting force, the piston will retract some distance, which verifies the existence of atmospheric pressure.

Take a syringe, push the piston to the bottom, plug the small hole at the front end with your fingers, pull the piston to the middle of the tube, then dip the finger blocking the small hole into the water, you will see the water enter the inside of the syringe, which verifies the principle of the pumping machine It uses atmospheric pressure to work.

In addition, you can use a syringe to demonstrate how to liquefy gases, verify the relationship between gas pressure and volume, and demonstrate the relationship between air pressure and the boiling point of liquids.

Example 2 Give you a sharpened long pencil and use it to design two physics experiments.

This is a good experimental question to cultivate the ability to observe, experiment, and innovate, and the pencil is also a often used stationery, so the experiment is easy to conduct.

Press the two ends of the pencil with the index finger and thumb respectively, and the finger indentation depth is different, indicating that "the size of the pressure is related to the size of the force area"; The pain in the fingers is also felt when the finger presses against the pencil, which again indicates that "the force is reciprocal".

Wrap a thin wire around one end of the pencil or press a thumbtapin into the end of the pencil so that it floats vertically in water and other liquids, and the density of the liquid can be determined by the depth of immersion in the liquid.

The diameter of the wire can be found by wrapping the thin iron wire tightly around a round pencil, and then measuring the total length d of the metal wire and copper in n circles with a ruler.

In addition, it can also be considered from the optical, thermal, and electrical aspects, for example, if a pencil is placed upright on the ground under sunlight or under a lamp, the shadow of the pencil will appear, indicating that "light travels in a straight line in the same homogeneous substance"; Heat one end of the pencil lead with an alcohol lamp, and after a period of time the other end of the pencil lead is also hot, indicating that "the pencil lead is a good conductor of heat"; The principle of a sliding rheostat can be illustrated by connecting one end of the wire to one end of the lead and sliding the other end on the lead of the pencil to change the length of the circuit connected to the circuit.

Fill the paper cup with water, cover the mouth of the cup with a screen, and then cover it with paper, turn the paper cup upside down, the paper does not fall, take away the paper, and the water does not come out.

Principle: Atmospheric pressure and surface tension of water.

Fun Science Experiments: Mints vs Coke Fanta Devil's Claw Conduct fun science experiments.

What is so difficult to do, what is the final exam is generally not difficult, as long as you master the basics and practice simple questions.

Remember a strange little experiment.

During today's class, the teacher asked us a strange question: why didn't a little boy lie on the sea and read and sell old books? As soon as the teacher's words fell, the students started to talk nonsense.

Some classmates said that he was lying on the swimming ring; Some say that he is lying on the Dead Sea. The teacher just smiled and didn't say anything.

Out of nowhere, the teacher conjured up a clear plastic cup, a raw egg, a spoon, and a small bag of salt. The teacher first asked a student to fill a cup with half a glass of water, and then gently put the egg in it, and the egg sank in an instant. I stared intently at the cup.

Then, the teacher took a small spoon and added salt to the cup one by one. We understood that the teacher was going to add a certain amount of salt to the cup to make the eggs float. However, four or five spoonfuls of salt were added.

The egg just twisted a few times with great reluctance, and then sank to the bottom of the cup and went to sleep. The classmates were anxious and shouted: "Add salt, add salt quickly."

The teacher added a few more spoonfuls of salt, but the eggs were still lying lazily at the bottom of the glass. At this time, we realized that the salt added was also like eggs, sinking to the bottom of the cup! So, the teacher took out the eggs and stirred them vigorously with chopsticks for a while, and the water became cloudy and the salt was gone.

When the teacher put the egg in again, it no longer slept as before, but stood up. It seems that success is not far off!

The teacher added a few more spoonfuls of salt to the cup, and after about half a minute, the egg floated, albeit in a state suspended in the water. The teacher took the chopsticks and stirred them in the water a few more times, and the eggs danced in the water "circle dance", which was so beautiful!

Then, the teacher added the last few spoonfuls of salt to the cup, and ah, the egg finally poked its head out of the water, and the students let out an exclamation of "wow". Then press the egg down with chopsticks, and it dances like a ballet dancer in the water and rises out of the water. I think:

If a little boy can lie on the sea and read a book, it must be that the sea water contains a lot of salt.

Finally, the teacher told us the answer to the question we asked in the lesson: the sea where the little boy was lying down and reading was the "Dead Sea". The salt content of seawater is more than 30%, and people will not sink if they lie down.

Today's experiment has taught me another common sense of natural science. When I get home, I'm going to try to see if sugar can make eggs float in the water, and if so, can MSG or something like that make eggs float too?