An electron can emit light (photons) through a process called electromagnetic radiation when it undergoes a transition from a higher energy state to a lower energy state. This emission of light occurs regardless of whether the electron is visible or not visible, as the visibility of an electron is not determined by its interaction with light.
In an atom, when an electron absorbs energy, it can be excited to a higher energy level. This excited electron is in an unstable state and tends to return to its lower energy state. During this transition, the electron releases the excess energy in the form of photons. These photons can have various wavelengths, including those in the visible spectrum, which can be detected by our eyes, making the electron's emission visible.
However, it's important to note that an electron does not necessarily need to interact with photons to emit light. Electromagnetic radiation can occur even in the absence of external photons. For example, an electron can undergo transitions between energy levels within an atom due to its interaction with the atom's own electromagnetic field. This interaction can lead to the emission of photons without any external light source.
Additionally, even when an electron is not interacting with other particles or fields, it still possesses intrinsic properties, such as its mass and charge. These properties are fundamental and exist independent of interactions with other particles. The visibility or invisibility of an electron is not determined solely by its interaction with other particles or photons but rather by the specific experimental conditions and detectors used to observe or measure it.
In summary, an electron can emit light (photons) through electromagnetic radiation when it undergoes transitions between energy states. This emission can occur whether the electron is visible or invisible, and it is not solely dependent on the interaction with external photons.