Let's start with a basic concept. The color of light is determined by its frequency. And higher frequency light has more energy than lower frequency light. As regards electrons shifting energy levels, when an electron wants to move to a lower energy level, it must radiate energy to do this. And the energy it radiates will be exactly the "right amount" for that electron to go to that lower energy leve. The greater the difference in the starting and finishing energy levels, the more energy the electron will have to radiate away. And this will determine what the energy of the photon will have to be. It will determine its frequency, and, therefore, its color.
The energy of the photon determines its wavelength or color. By looking up wavelength absorption or light absorbance & transmittance, you will discover an amazing lesson on spectron photography. :)
The difference in energy between the energy levels determines color of light emitted when an electron moves from one energy level to another.
After electron capture a neutrino is released.
Only one photon is produced per electron in any de-excitation. The number of energy levels it drops only determines the energy of the photon emitted.
a photon is emitted or absorbed
No. Energy is emitted when an electron moves to a closer shell (closer to the nucleus).
The difference in energy between the energy levels determines color of light emitted when an electron moves from one energy level to another.
No. An electron may be emitted in some cases, though.
After electron capture a neutrino is released.
A positive electron (positron) is emitted.
the gamma ray.
Many particles can be emitted from radioactive decay. We have Internal Conversion in which a nucleus transfers the energy to an electron which then releases it. There is also Isometric Transition which is basically the gamma ray (photon). There is the decay in which a nucleon is emitted. In this scenario we can have an alpha decay (in which an alpha particle decays), a proton emission, a neutron emission, double proton emission (two protons are emitted), spontaneous fission (the nucleus brakes down into two smaller nuclei and/or other particles) and we have the cluster decay (where the nucleus emits a smaller nucleus). There is the beta decay too. There is the Beta decay (electron and electron antineutrino are emitted), positron emission (a positron and an electron neutrino are emitted), electron capture (an electron is captured by the nucleus and a neutrino is emitted), bound state beta decay (the nucleus decays to an electron and an antineutrino but here the electron is not emitted since it is captured into a K-shell), double beta decay (two electrons and two antineutrinos are emitted), double electron capture (the nucleus absorbs two electrons and emits two neutrinos), electron capture with positron emission (an electron is absorbed and a positron is emitted along with two neutrinos), and double positron emission (in which the nucleus emits two positrons and two neutrons).
The shorter the wave length the more energy. The further the electron falls, the more energy that will be emitted and the shorter the wavelength.
In this context, we call an electron a beta particle.
Only one photon is produced per electron in any de-excitation. The number of energy levels it drops only determines the energy of the photon emitted.
a photon is emitted or absorbed
Frequency determines color. Frequency is determined by the origin of the photon, i.e. emitted from an excited atom.
Its right in the book (in bold) and has a key next to it.