You must have seen intelligence workers on TV, don't you think they are mysterious? Now let's be an intelligence agent. We're not passing on information, but writing it, using onions!

1 onion

1 piece of white paper 1 alcohol lamp

1.Cut off the white onion.

Use it to write your name on a piece of white paper.

Let the paper dry and bake it on the fire.

Your name soon came out.

1.Don't rub your eyes with the hands that have peeled onions. 2. When you put out the alcohol lamp, you should not blow it with your mouth, but cover it with a lamp.

Why is this happening?

It turns out that the juice of onion is left on the paper, which can change the paper and produce a transparent film. Because this substance is easier to catch fire than paper, when it is baked on an alcohol lamp, the paper is not lit and it is first burnt, and the words written in scallion are displayed!

Besides onion juice, can you think of anything to write information with?

What do you have in mind? Write it down quickly!

2. Making submarines out of eggs

Do you believe that eggs can rise and fall freely like submarines without changing the shape and contents of eggs? Let's try it together 1

1 egg

1 glass

salt

water

1.Put the egg in a glass filled with half a glass of water. When the hand is released, it is found that the egg will purr and sink to the bottom of the glass.

2. Take out the eggs and add salt to the water to prepare a high-concentration salt solution, then immerse the eggs in the salt solution and loosen your hands.

Eggs will stagger to the surface.

Why is this happening?

Put the eggs gently and don't let the water ripple.

Whether an object can float on the water surface mainly depends on the relationship between its gravity and buoyancy. When gravity is greater than buoyancy, the object sinks, otherwise, the object can float on the water surface, and when they are equal in size, the object can float in the water.

The ups and downs of eggs are precisely because the density of eggs is a little higher than that of clear water (the density of eggs is about1.07g/cm3, while the density of clear water is1.0g/cm3. When an egg is immersed in clear water, the gravity is greater than the buoyancy, so the egg sinks. When eggs are immersed in salt water, the density of salt water is greater than that of eggs, and the gravity on eggs is less than buoyancy, so they will emerge from the water.

Try changing to other objects and determine which objects are denser than water. Which objects are less dense than water?

Be sure to do it! What do you have in mind? Write it down quickly!

3. The inseparable balloon

Two small balloons are like our friends, sometimes inseparable and sometimes ignoring each other, so when will the two balloons attract each other? Under what circumstances will they be mutually exclusive? Let's find the answer together! 2 balloons filled with gas 1 string 1 piece of cardboard

1.Inflate two balloons separately and tie a knot at the mouth, and connect two small balloons together with a string.

2. Rub the balloon on your hair (or sweater).

3. Lift the middle part of the string so that two small balloons can get together.

4. Put the cardboard between two balloons and observe the phenomenon.

1.When the middle part of the string is lifted, the two balloons immediately separate.

When the cardboard is placed between two balloons, the balloons are attracted to the cardboard.

Why is this?

Don't rub the balloon with your hair too hard, or you'll break it!

When the balloon rubs against the hair, it produces the same charge, and there is repulsion between the same charges, so when the two balloons get together, they immediately separate, and the electricity on one balloon repels the electricity on the other balloon. When a cardboard is placed in the middle, the electricity on the two balloons attracts them to the cardboard. Because different kinds of charges are induced on the cardboard, opposites attract each other, so that two small balloons get together again through the cardboard!

This experiment tells us a way to verify whether the same object is charged. Do you think it can be explained by other small experiments? Be sure to think about it!

What do you have in mind? Write it down quickly!

4. My cooking skills-scrambled eggs with tomatoes

Mom and dad cook for you at home, right? Have you ever thought about making some side dishes to repay them? Ok, today let's study the famous tomato scrambled eggs 1

2 fresh tomatoes

2 eggs

spring onion

oil

salt

sugar

Chicken essence (monosodium glutamate is also acceptable)

bowl

chopsticks

1.Slice the tomatoes, break the eggs in a bowl (mix well with chopsticks), cut the shallots into chopped green onions and put them in a small bowl.

2. Light the fire, put it on the pan, and then drain the oil after the pan is hot. When the oil is 60% to 70% hot, pour the eggs in, and then smash them evenly with a spatula. Don't let the eggs form a cake.

3. Stir-fry the tomatoes a few times, then add a spoonful of salt and stir-fry them a few times. Turn down the heat until the red juice is fried or the tomato skin is about to take off, add a little chicken essence and sugar and stir well.

4. Turn off the fire and sprinkle chopped green onion on it to get out of the pot!

Don't use too much oil when frying, it will become very greasy and lose its fragrance; If there is too little oil, it will make the eggs paste and smell burnt. Why is this happening?

The main ingredient of eggs is protein, which will change when the temperature is too high, and it will become mushy and zoom!

Will protein's nutritional value change after the eggs are boiled at high temperature? How to cook to make eggs taste better? Try it when you think of it!

What do you have in mind? Write it down quickly!

Balloon car

Material preparation: balloons (of the same size and different sizes), toy cars (of the same size and different sizes), waste pen tubes and transparent tape.

Production method:

(1) Put the balloon on the ~ end of the waste pen tube and fix it with a thread. Then blow the balloon through the pen tube. After blowing the balloon, plug the other end of the pen tube with a pen cap or something to prevent gas from flowing out.

(2) Fix the balloon on the car with adhesive tape, so that the balloon powered car is ready.

Experimental operation:

Let the children pull out the pen cap and let the car move forward. Or let two children have a race to see whose car goes further.

Teachers' guidance suggestions:

● Provide small toy cars for children so that they can feel the power of airflow more deeply.

● When fixing the balloon on the car with scotch tape, please ask two children to cooperate with each other, and pay attention to remind the children not to break the balloon.

● Remind children to explore the relationship between the size of the balloon and the size of the car and the speed and distance of the car through observation.

Expansion and substitution:

◆ Balloons can be glued to other toys of suitable size. Please observe the relationship between the size of balloons and the running speed and distance of toys.

◆ You can make your own car with cardboard, straws and thin wire. (See "Balloon Powercar Figure 2. )

Small scientific knowledge

Balloons are made of rubber and have good flexibility. When the pen cap is pulled away, the inflated balloon will automatically contract, and the air in the balloon will be suddenly discharged outward, generating a force, which is the driving force of the toy car. Under the condition that the size of the toy car is unchanged, the more gas in the balloon, the greater the power, the faster the toy car travels and the farther it runs. Under the condition that the gas in the balloon remains constant, the smaller the toy car, the slower the driving speed and the closer the distance.

An unbreakable egg

[Activity objective]

(1) is not afraid of failure and dares to overcome difficulties in the experiment.

(2) In the operation, we can negotiate with our peers and cooperate with them to solve the difficulties in the operation.

(3) We can actively use our brains to design packaging methods that make eggs unbreakable.

[Important and difficult activities]

Children can explore ways to package eggs according to their own life experience.

Can make the eggs packaged by oneself have the functions of shock prevention and fixation.

[Activity preparation]

(1) Materials collected with children: paper boxes, plastic boxes, foamed plastics, rice pineapples, cotton, newspapers and cardboard.

(2) Cooked eggs, rubber bands, transparent tapes, paper clips, scissors, wool, sticky nails and erasers.

[activity process]

1, stimulate interest:

Teacher: A few days ago, children * * * collected a lot of packaging boxes. Through observation, children found that packaging can protect things, fix things, and then put some soft materials on them, so they are not easy to break.

Show the yo-yo box, and observe and analyze the function of the box.

2. Ask questions: What should children pay attention to when they are transporting eggs and packing eggs today?

3, guess and record:

Teacher: Work in pairs to discuss what materials are needed to package eggs. How to pack it?

Teacher: You have come up with so many good methods. Let's give it a try and see which method can be used to package broken eggs.

4, experimental verification and record the results:

Key guidance:

(1) The container should not be too small, and there should be enough space to fill with soft materials.

(2) the eggs should be placed in the middle, so that the eggs should be protected by soft materials up and down and around.

(3) The filler should fill the container to fix the eggs.

Teachers pay attention to guiding children to make bold attempts in activities.

5. Communication and summary: Is your experiment the same as your guess? Why?

6, activity extension: stand in a higher place to try. For example, stand on a chair and lift it up so that the egg can fall and break.

The birth of bubbles

Activity objectives:

1, through the hands-on experimental operation, know the hollowing out.

1, through hands-on experiments, make various bubble blowing tools, explore various methods of blowing bubbles, and experience the joy of success.

2, in the experiment, cultivate children's habit of careful work and careful observation and the ability to explore problems.

3. Learn to keep simple records. Activity preparation:

Large jelly boxes/kloc-0 per person, each containing half a cup of detergent water; 15cm long telephone lines, one record sheet and one pen; 25cm long telephone line per person 1 root, 2-3 pieces of paper per person, straws and some plastic toys; A big record sheet for teachers.

Record Form for Teachers: Record Form of Small Experiment "Interesting Bubble"

Large class science: the method of blowing bubbles

A record sheet for children: A small experiment "Interesting Bubble" records the phenotypic activity process;

Introduction: Teachers should play more bubble games with children.

Experiment 1:

1, show materials, introduce materials, record forms and operation methods.

2. Guess: What shape of bubbles will be blown out by blowing bubbles with a ⅹ-shaped tool? (Children make bold guesses, and the teacher records the children's guesses on the record sheet.)

3. Requirements:

① Record the shape of the folded tool first, then experiment and record the experimental results. Have a look. Is it the same as the guess?

② When blowing bubbles, don't touch the tools with your mouth, don't aim at your partner's face and blow bubbles. If you accidentally spray bubble water on your face, wipe it with a paper towel.

4, children's experiments, teachers comprehensive observation, timely support and help. Focus on guiding children to record and guess first, and then verify by experiments, and encourage children to try more bubble blowing tools in several shapes.

5. Communication:

A, peer exchange their own experimental findings.

B, concentrated communication: ① What shape tool did you just fold to blow bubbles? What kind of bubbles are blown out? Is it what you guessed before the experiment? (Ask individual children to bring a recording form to tell the whole class about his experimental findings, and the teacher will record it according to what the children say.)

2 Guide children to discover and question: Do you have any findings or questions to ask after the experiment and reading the record sheet? (Teachers answer and question according to children's questions)

Summary: The bubbles blown by various tools with different shapes are round, because the surface tension of bubble water is at work; Explain that what you guess is not necessarily correct, you must do it yourself.

Experiment 2:

1, exciting: There are many ways to blow bubbles …

2. Show new materials (long telephone lines, pieces of paper, etc.), and introduce materials and operation methods.

3. Suggestion: You can make more tools to try. Children can cooperate with two people or three people. The more ways to see who thinks, the more kinds of bubbles will be blown out.

4, children's experiments, teachers encourage children to make more tools and come up with more ways to blow bubbles.

5. Children go to the playground to play the game of blowing bubbles and end freely.

Capsules capable of somersaulting

Teaching plan for scientific activities in kindergarten: Capsules capable of tumbling Xia Cuiying (teacher) 2011-03-16 Teaching plan for scientific activities in kindergarten: Capsules capable of tumbling: March 2009-1108: 00.

Teaching plan for scientific activities in kindergarten large classes: a capsule that can somersault.

Design intent:

One morning, Zhu Lihui, a child in our class, brought a "McDonald's" toy, a clown who turned upside down. The children surrounded him and asked him to play again and again. At this time, a child asked, "Why does it tumble and keep turning?" Everyone started a discussion, and some said that it was because Zhu Lihui turned the climbing pole up and down by hand; Some say that clowns have magnets … how can children explore this scientific principle? I designed this activity "Capsules capable of tumbling", mainly to ask them to explore the interesting phenomenon that the shift of the center of gravity of an object will change the direction of the object, and through the operation, let them know that the special shift of the center of gravity will be restricted by the shape, size and weight of the object.

Activity objectives:

1, through exploration and operation, I feel the scientific principle of capsule somersault, so I like scientific activities.

2, will use simple materials for experiments, and record the results according to the operation.

3. It is the principle of shifting the center of gravity to understand that the capsule will somersault.

Activity preparation:

1, one set of experimental equipment for children: capsules, iron balls, disposable bowls and other experimental materials (soybeans, twigs, rice grains, stones, rags).

2. Forms and pens for recording experimental results.

3. Courseware.

Activity process:

(a) observation and comparison, lead to guess.

1, the teacher prepared ordinary capsules and capsules filled with iron balls in the children's bowls for children to observe and compare, and found that the capsules filled with iron balls would tumble, and the ordinary capsules only rolled in the bowls.

2. Children make guesses.

(2) experimental operation, to explore what will be somersaulted in the capsule.

Children try to put different experimental materials into the capsule, let the capsule somersault, children record the operation results, and tell their own operation process according to the records.

Summary: putting a small iron ball into the capsule will make the capsule turn over.

(3) Experiment again to compare the differences between iron balls and other materials.

Children feel the difference between iron balls and other materials by pinching, touching, weighing and watching, and express their own process results in words.

Summary: Because the iron ball is round and has a certain weight, it can roll in the capsule, which changes the center of gravity of the capsule and causes the capsule to somersault.

(4) Watch the courseware to further perceive the principle of center of gravity shift.

(E) expand thinking to guide children to tell the objects made by using the principle of center of gravity shift in life.