Ingredients: a yogurt cup, two rubber bands, a glass of water and two transparent plastic films.

Principle: The spherical container can act as a magnifying glass, which we also call a lens.

Make a small rainbow

Material: a basin of clear water and a flat mirror.

Principle: Mirrors and water bodies refract sunlight and then project it onto the wall.

Bake eggs in the sun

Ingredients: a raw egg, a piece of black paper, an aluminum foil paper, a small glass bottle (which can hold eggs) and a large glass bottle.

Principle: the glass bottle has the function of concentrating sunlight in one focus and heating up rapidly; The choice of black paper is based on the principle that black absorbs all light and accelerates absorption and temperature rise.

4. Crazy balloons

Material: a balloon, a ping-pong ball.

Principle: Putting table tennis into a balloon will increase a gravity interference, which will make the trajectory of the balloon very strange.

Step 5 grow small trees

Materials: a box of toothpicks, a rubber band, a small dish filled with water, a coffee filter paper, a watercolor pen (color as you like) and a pair of scissors.

Principle: Water rises upward through the gap between toothpicks, which is a capillary phenomenon. This gap is similar to the vessel in the xylem of a tree. This tiny tube carries water from the roots to the leaves.

Extended data

The significance of children doing small scientific experiments;

First, the experiment itself is full of curiosity and unknowns.

For children, curiosity is nature. Through the experiment, it not only satisfies the curiosity, but also cultivates the spirit of focusing on exploration.

Second, cultivate children's ability to observe and remember carefully.

Scientific experiments must be sloppy. If you don't listen to the teacher carefully, you won't know the steps and precautions of the experiment. Not only need to listen carefully, but also need to do it seriously.

Third, cultivate a sense of cooperation.

There are many experiments that require the cooperation of many people and groups. Everyone should be careful about what he is responsible for. Only when everyone has done it well can the whole project be completed perfectly.

Fourth, cultivate awareness of rules.

The purpose of the experiment is to find the law of reaction and synthesis of things through failure and exploration, and then understand its essence.