The spark effect you observe with charged particles is commonly seen in situations where there is a buildup and release of electrical energy. It occurs due to the phenomenon of electrical discharge.
When an object becomes charged, it means that it has gained or lost electrons, resulting in an imbalance of positive and negative charges. This charge imbalance creates an electric field around the object. If the electric field becomes strong enough, it can cause the air or surrounding medium to break down and become ionized.
During ionization, electrons in the air molecules are stripped away, creating positively charged ions and free electrons. The electric field accelerates these free electrons, giving them enough energy to collide with other atoms or molecules in the surrounding air. These collisions cause further ionization, creating a chain reaction called an electron avalanche.
The electron avalanche rapidly releases a large amount of energy and produces a visible discharge, which we perceive as a spark. The spark is essentially a flow of electrons through the ionized air or other medium. It is accompanied by the emission of light and heat due to the high energy of the electrons and the excitation and de-excitation of atoms in the medium.
The appearance and behavior of the spark depend on various factors, including the magnitude and polarity of the charge, the distance between the charged object and a conductor or ground, the nature of the medium (such as air, gas, or liquid), and the specific conditions present during the discharge.
Overall, the spark effect is a result of the movement of charged particles, specifically electrons, in an ionized medium, leading to the emission of light and heat.