Sähkönsäilymisen

Sähkönsäilymisen, or the conservation of electric charge, is a fundamental principle in physics stating that the total electric charge in an isolated system remains constant over time. This means that electric charge cannot be created or destroyed, only transferred from one object to another or redistributed within a system.

The principle of charge conservation is a cornerstone of electromagnetism and is observed in all known physical processes. For example, when a neutral object is rubbed against another, electrons can be transferred, resulting in one object becoming positively charged and the other negatively charged. However, the total charge of the two objects combined remains the same as it was before the rubbing.

In nuclear reactions, such as radioactive decay, charge is also conserved. For instance, in beta decay, a neutron transforms into a proton, an electron, and an antineutrino. While the neutron is neutral, the proton has a positive charge and the electron has a negative charge. The net charge before and after the decay remains zero.

Mathematically, the conservation of electric charge can be expressed by the continuity equation, which relates the change in charge density in a region to the electric current flowing out of that region. This equation is a direct consequence of the conservation law and is essential for understanding many phenomena in electrodynamics. The principle is universally applicable and has been rigorously tested and confirmed through numerous experiments.