What phenomena are generally accompanied by chemical reactions?

Chemical reactions are usually accompanied by luminescence, heat generation, discoloration, formation of precipitates, etc.

The essence of a chemical reaction is the process of breaking old chemical bonds and forming new chemical bonds.

The reaction is often accompanied by luminescence, heat generation, discoloration, formation of precipitates, etc. The basis for judging whether a reaction is a chemical reaction is whether the reaction generates new substances. According to the chemical bond theory, whether a chemical reaction is a chemical reaction can be judged based on whether there is the breaking of old bonds and the formation of new bonds during the change process.

Extended information:

Under the action of hydrochloric acid, the color of purple cabbage changes from purple to red. This work is from the chemistry photography series "Beautiful Chemistry" of the University of Science and Technology of China. When shooting, different chemical substances turn into brilliant colors and textures after contact, just like exquisite modern paintings.

It is reported that the three professors who participated in the shooting first conducted small-scale experiments to familiarize themselves with and master the shooting techniques and timing, and then carried out actual shooting. After completing the shoot, they uploaded the photos to their website, where they attracted a lot of attention as soon as they were uploaded. The "Beautiful Chemistry" series demonstrates chemical reactions including precipitation, crystallization, bubbling, and metal displacement.

In order to ensure the safety of filming, they did not choose potentially dangerous chemical reactions. The first step in the entire shooting plan is to conduct research, select suitable chemical reactions and then conduct experiments to ensure that these chemical reactions can present an aesthetic worth photographing. After determining the appropriate chemical reaction, they optimize various reaction parameters and shooting parameters to ensure that the perfect image is captured.

People's Daily Online - Chemical reactions are as romantic and gorgeous as modern paintings