Elementary education: a simple and interesting scientific experiment

Thinking: Without glue, tape and other things, newspapers can stick to the wall without falling off. Do you know why?

Material: 1 pencil; 1 newspaper.

Steps:

1. Spread the newspaper and lay it flat on the wall.

2. After a few quick rubs on the newspaper with one side of the pencil, the newspaper won't fall off just like sticking to the wall.

3. Lift a corner of the newspaper, and then let go, and the lifted corner will be sucked back by the wall.

Take the newspaper off the wall slowly and pay attention to the static sound.

Description:

1. Wipe the pencil to charge the newspaper.

2. The charged newspaper was sucked to the wall.

When the indoor air is dry (especially in winter), if you take down the newspaper from the wall, you will hear the crackle of static electricity.

Creation: Please have a try. What else can be stuck to the wall by static electricity without glue?

Separation of pepper and salt

Thinking: I accidentally mixed the kitchen condiments: pepper and salt. How can I separate them?

Ingredients: pepper, salt, plastic spoon, small dish.

Operation:

1. Mix salt and pepper.

2. Stir well with chopsticks.

3. Rub the plastic spoon on the clothes and put it on the salt and pepper.

4. Pepper sticks to the spoon first.

5. Move the plastic spoon down slightly.

6. After salt, stick it on the spoon.

Explanation:

Pepper is electrostatically adsorbed earlier than salt because its weight is lighter than salt.

Create:

Can you separate other mixed materials in this way?

Inflatable balloon

Thinking: When will two balloons attract each other and repel each other?

Material: 2 inflatable balloons, 1 string, 1 cardboard.

Operation:

1 Inflate two balloons separately and tie a knot in your mouth.

Connect two balloons with a thread.

Rub the balloon on your hair (or sweater).

Lift the middle part of the rope and the two balloons will separate immediately.

Put the cardboard between two balloons, and the electricity on the balloons makes them attracted to the cardboard.

Explanation:

The electricity on one balloon repels the electricity on the other balloon.

The electricity on the two balloons attracts them to the cardboard.

Creation: Can other small experiments be used to illustrate that balloons are charged?

Lovely watermark

Thinking: The beautiful patterns on rice paper are not drawn, but how are they made?

Materials: 1 washbasin, 1-2 rice paper, 1 chopsticks, 1 cotton swab, 1 bottle of ink and water (about half a basin).

Operation:

1. Pour half a basin of water into the washbasin and gently touch the water surface with chopsticks dipped in ink. You can see that the ink expands into a circle on the water surface.

2. Wipe the scalp with a cotton swab for two or three times.

3. Then touch the center of the ink circle and see what happens.

4. Gently cover the calligraphy paper on the water, and then pick it up slowly. What patterns are printed on the paper?

Explanation:

1. When the cotton swab touches, the ink will swell into an irregular circular pattern.

2. A small amount of oil on the scalp rubbed by cotton swabs will affect the mutual pulling force of water molecules.

3. The watermark will present irregular concentric circles.

Create:

Try other methods to change the ink pattern on the water surface.