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Alpha emission happens when an unstable nucleus ejects an alpha particle to become more stable. An alpha particle is essentially a bundle made up of two protons and two neutrons. This is exactly what makes up a helium-4 nucleus.
When a nucleus ejects an alpha particle, its atomic number decreases by two, and its atomic mass number decreases by four. Here's how it works:

• The atomic number drops because the nucleus loses two protons.
• The atomic mass number decreases as the nucleus also loses two neutrons along with those protons.

So, an atom undergoing alpha emission transforms into a completely different element located two places left on the periodic table. This is because the loss of protons changes the element's identity. The alpha particle is often symbolized as \(_{2}^{4}\)He, reflecting its helium-like nature. This type of radiation is relatively heavy and doesn't travel far through the air, but it can be stopped by something as thin as a sheet of paper. Because of their size, alpha particles are not deeply penetrating, but they can cause damage if ingested or inhaled into the body.

Beta emission is a fascinating process occurring in the nucleus of an atom. During this type of radiation, a neutron turns into a proton and emits a beta particle, which is essentially an electron. This process results in an increase in the atomic number by one, but the mass number stays the same.
Here is a breakdown of the process:

• Neutrons in the nucleus decay into protons.
• An emitted beta particle \(_{-1}^{0}\)e carries away a small amount of energy and charge.

Despite the atomic mass number staying constant because the proton count increases by one while the neutron count decreases by one, the atomic number goes up by one. This means the atom changes into a new element that sits one place to the right on the periodic table. Beta particles are much lighter than alpha particles and can penetrate materials better, but they can be stopped by materials like aluminum foils. These emissions are important in both natural processes, like radioactive decay, and in technological applications, such as medical imaging.

Gamma emission is quite unique compared to alpha and beta emissions. It involves the release of energy in the form of gamma rays from the nucleus of an atom but does not change the composition of the atom. This emission occurs when the nucleus seeks a more stable energy configuration after undergoing another type of radioactive decay.
In gamma emission:

• The atomic number and mass number remain unchanged.
• This type of radiation is represented by \(_{0}^{0}\)γ

Gamma rays are pure energy, not particles, and hence are highly penetrative compared to alpha and beta particles. They can travel significant distances and can even pass through many materials, requiring dense substances like lead or several inches of concrete to block them effectively. Due to their penetration power and energy, gamma rays are used in medical treatments such as cancer radiotherapy and are also important in various forms of spectroscopic analysis.