You types of electrical charge were defined after numerous studies carried out in order to identify the phenomena of electricity.
Who initially observed the repulsion caused by equal electrical charges was Otto Von Guericke, but it was in the mid-1730s
that Frenchman Charles DuFay, through studies and experiments carried out, was able to demonstrate the existence of attraction and repulsion between electrical charges.
Anyway, after countless researches, experiments and observations made with protons, electrons and neutrons, physicists reached the following conclusion:
Attraction and repulsion between electrical particles
Neutrons have also been studied by numerous scientists, who have observed that neutrons do not generate any kind of charge. electrical (neither positive nor negative), this regardless of whether they are in the presence of protons, electrons or even between neutrons.
They, the neutrons, do not produce any kind of electrical force.
Due to these facts, it was concluded that there were two types of electrical charges, one for the proton and one for the electron.
By convention, it was defined that the charge of the electron would be mathematically represented by the negative sign (the charge being then negative) and that of the proton by the positive sign (positive charge).
With this we identified that:
• Positive electrical charges repel each other.
• Negative electrical charges repel each other.
• Electrical charges with opposite signals (positive and negative) attract each other.
Attraction and repulsion between loads
By Talita A. angels
Graduated in Physics
Brazil School Team
Electricity - Physics - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/fisica/os-tipos-carga-eletrica.htm