Simple Science - Digest Experiences # 36

I continue the publication of our digests "Simple Science". By the way, today is the 36th issue in three years.

In today's release:

• light bulb in liquid nitrogen;
• chemical focus with a scarf;
• curvature of water;
• quantum levitation.

')

Bulb in liquid nitrogen

ATTENTION: breaking the glass flask, we exposed the contacts to which the current is 220v. This voltage is life threatening!

The experiment clearly shows how an open spiral incandescent lamp quickly burns in air and remains unscathed while immersed in liquid nitrogen. It can be concluded: nitrogen is not an oxidizing agent and does not conduct electric current in liquid form.

During the production of incandescent bulbs, as exemplified by the one we smashed before the experiment, they are filled with inert gas. One of these gases is argon, and sometimes nitrogen.

Chemical focus with a handkerchief

Experience is based on the formation and destruction of crystalline compounds. Demonstrates discoloration of compounds when water is added or removed. Initially, the solution of cobalt chloride has a pink color. When heated, water from the surface of the shawl evaporates and cobalt chloride precipitates as a pink crystalline hydrate. Further heating leads to the destruction of the aquacomplex. So at temperatures above 110 degrees Celsius, the compound turns into anhydrous CoCl2 having a blue color. As soon as we add water again, the water is embedded in the crystal lattice, a crystalline hydrate is formed again and the scarf becomes pink again.

Water curvature

The video made an inaccuracy in the voice acting: the curvature of the jet can be seen directly on the camera, but only this camera should have adjustable shutter speed (tent), which should be as low as possible and carry out the experience either on the street on a sunny day or use additional lighting. But not all cameras, especially amateur cameras, have such a function. We set our task to show how this can be done even at home. For example, there are cameras that shoot at a frequency of 240 fps, and the iPhone 6 already has the possibility of such shooting.

Quantum levitation

I remind about our books to those who have not had time to buy a gift for their child or nephew for the new year.