katódos

Katódos is a term that refers to the negative electrode in an electrochemical cell or electronic device. In electrolysis, the cathode is the site where reduction occurs, meaning it attracts positively charged ions (cations) from the electrolyte, and these ions gain electrons. In a galvanic cell, such as a battery, the cathode is where the positive terminal is located, and it is where the reduction reaction takes place.

The term "cathode" originates from the Greek words "kata" (down) and "hodos" (way), signifying the path of current flow. In vacuum tubes and cathode ray tubes, the cathode is a heated filament or surface that emits electrons through thermionic emission. These electrons are then accelerated towards a positively charged anode. In solid-state devices like diodes, the cathode is the semiconductor region that receives electrons from the external circuit. The polarity of the cathode is always negative with respect to the anode in a DC circuit. Understanding the cathode's function is crucial in comprehending various electrochemical and electronic phenomena, from battery operation to the functioning of display technologies.