In order to fall closer to the nucleus an electron must have ________
It must have a quantum mechanically allowed orbit there. A few isotope nuclei do capture electrons that get too close. This results in radioactive or X-ray emission.
If you are looking for a short answer, I don't have any. The electron must have negative charge to have any stable orbit at all.
In order to fall closer to the nucleus, an electron must have less energy.
To understand why, we need to discuss the concept of energy levels in an atom. In the Bohr model of an atom, electrons exist in distinct energy levels or shells around the nucleus. These energy levels are labeled with principal quantum numbers (n = 1, 2, 3, and so on), with higher numbers indicating higher energy levels located further from the nucleus.
According to the Bohr model, electrons can transition between different energy levels by either absorbing or emitting energy in the form of photons. When an electron absorbs energy, it moves to a higher energy level further away from the nucleus. Conversely, when an electron emits energy, it falls to a lower energy level closer to the nucleus.
The energy of an electron is influenced by its distance from the nucleus and the attractive force between the electron and the positively charged nucleus. As an electron moves closer to the nucleus, the attractive force increases, and the electron's potential energy decreases. This decrease in potential energy corresponds to a decrease in the electron's overall energy level.
Therefore, for an electron to fall closer to the nucleus, it must release energy in the form of a photon. This energy release can occur through various processes, such as the emission of light or heat. By releasing energy, the electron transitions to a lower energy level, moving closer to the nucleus.