What does the word "technology" remind you of? Bottles and jars in scientists' laboratories? Scientists in science fiction films, Edison and Newton.

Why does iron rust?

I wonder if you have noticed that iron will "grow" a red thing after a period of time, which is the question of whether it rusts. Then why does iron rust? I decided to do this experiment to find out the problem.

I took out the same nail from the toolbox and four bottles of beauty liquid, baking soda and salt used by my mother from the cupboard. The experiment began. These four beauty liquid bottles contain water, salt, air and carbon dioxide. After nailing each bottle of beauty liquid, I put all four bottles of beauty liquid on the balcony, and I can see the effect in three days.

Three days later, I came to the balcony, picked up these four bottles and took out the nails. The result is this:

Air: It's all rusty.

Carbon dioxide: no rust.

Water: It's all rusty.

Salt water: all rust, embroidered layer thickened.

It turns out that rust is the oxidation of iron. If rust is not removed, the life of iron will be shortened.

two

Does the same volume of liquid weigh the same? I want to do this experiment to find out the problem.

I took out a simple balance from the kitchen,10ml honey,10ml water and10ml oil. I put honey and water on the balance first, and the water end is tilted, indicating that honey is heavier than water; I put water and oil on the balance again, and the oil end tilted up, indicating that water is heavier than oil.

So, since they are the same size, why are they different in weight? I checked the information on the computer, and it turns out that the volume is the same, but the density is different. Honey is heavy because of high density, and oil is light because of low density.

Xie Yingze, Class 6, Grade 3, Wu Tie Primary School

Instructor: Li Zhou