Alpha decay decreases the atomic number by two.
Beta- decay increases the atomic number by one.
Beta+ decay decreases the atomic number by one.
Gamma decay does not change the atomic number. However, gamma decay is often incidental to a precipitating alpha or beta event that upsets the energy equilibrium in the nucleus, so the two are not unrelated.
An alpha particle is a helium nucleus, which consists of 2 protons and 2 neutrons. When an unstable nucleus emits an alpha particle, it loses 2 protons, which means its atomic number will be reduced by 2.
The mass does not change much. The Atomic number will increase though.
Helium nucleus
alpha particle, He nucleus
Nucleus minus two protons and minus two neutrons (alpha particles are 4He nucleii)
An alpha particle is a helium nucleus, which consists of 2 protons and 2 neutrons. When an unstable nucleus emits an alpha particle, it loses 2 protons, which means its atomic number will be reduced by 2.
The mass number goes down by 4, and the atomic number goes down by 2 when a nucleus loses an alpha particle. XYZ --> alpha emission --> X-2Y-4Q + 24He2+
A+. . .. . . . helium nucleus
Two less, since the alpha particle takes away two protons.
The mass does not change much. The Atomic number will increase though.
Helium nucleus
An alpha particle has 2 protons and 2 neutrons. This would make the atomic number decrease by 2 and the Atomic Mass will decrease by 4.
alpha particle, He nucleus
Setting aside spontaneous fission, which is the natural "splitting" of an atom into fissin fragments, it is alpha decay that results in the greatest change in atomic number. The alpha particle carries off a helium-4 nucleus, which is a pair of protons and a pair of neutrons. Atomic number of an element involved in an alpha decay goes down by two.
Nucleus minus two protons and minus two neutrons (alpha particles are 4He nucleii)
226Ra------------alpha particle----------222Rn (radon, a radioactive gas)
It depends on what caused the gamma event in the first place.Strictly speaking, gamma radiation is caused by the de-excitation of the nucleus, so the atomic number (and Atomic Mass) does not change during a gamma event.However, the gamma event is usually precipitated by some other event, such as a beta or alpha decay that does change the configuration of the nucleus. An alpha event reduces the atomic number by 2 (and reduces the atomic mass by 4), while the beta event increases the atomic number by 1 (and does not change the atomic mass very much).Its actually more complex than that, but the answer to the original question is that nothing really happens to the atomic number during a gamma event.