Identify the particle represented by each symbol as an alpha particle, a beta particle, a gamma ray, a positron, a neutron, or a proton. (a) Ip (b) \({ }_{2}^{4} \mathrm{He}\) (c) \(+1^{0}\)

An alpha particle, denoted by the symbol _2^4He, is a type of subatomic particle that plays a key role in the field of nuclear physics. It can be described as a helium nucleus that has been stripped away from its two electrons and thus consists of two protons and two neutrons. These particles are positively charged and are emitted during the radioactive decay of certain heavy elements, such as uranium and radium.

Due to their composition, alpha particles have a relatively large mass in comparison to other types of radiation, like beta particles and gamma rays. This heft contributes to their inability to penetrate materials deeply; a sheet of paper or the outer layer of human skin is typically enough to stop them. However, when they do interact with matter, alpha particles can cause significant ionization due to their charge and mass.

A beta particle is a high-energy, high-speed electron or positron that is emitted from a decaying atomic nucleus in a type of radioactive decay known as beta decay. Beta particles can be either negatively charged (electrons) or positively charged (positrons).

In beta decay, a neutron transforms into a proton (or vice versa), resulting in the emission of the beta particle and an antineutrino (or neutrino). Negatively charged beta particles (β-) are electrons, while the positively charged ones (β+) are called positrons. Beta particles are more penetrating than alpha particles but less than gamma rays. They can pass through paper but are typically stopped by thin layers of metal or plastic.

Protons are one of the key building blocks of atomic nuclei, along with neutrons. They are positively charged subatomic particles, symbolized as p or p+. The number of protons found in an atom's nucleus, defined as the atomic number, uniquely identifies an element. For instance, every atom of hydrogen has one proton, which categorizes it as hydrogen.

Protons are relatively heavy when compared to electrons and possess a charge equal in magnitude but opposite in sign to an electron. The stability and chemical characteristics of atoms and molecules are significantly influenced by the arrangement and interaction of protons within atomic nuclei.

Neutrons, represented by the symbol n or n^0, are subatomic particles found in the nucleus of an atom, along with protons. They play a vital part in the stability of the nucleus. One of the unique properties of the neutron is its lack of charge—it's electrically neutral. This differentiates it from the positively charged proton.

Neutrons are slightly heavier than protons and are responsible for the isotopic differences among elements. Since they do not have any electric charge, they do not ionize atoms in the same way that charged particles (like protons and electrons) can; however, they can lead to ionization indirectly through nuclear reactions.

A positron is the antiparticle or the antimatter counterpart of the electron, which has the same mass as an electron but carries a positive charge. It is symbolized by e+ or β+. In situations where a proton in a nucleus is converted into a neutron, a positron is emitted along with a neutrino - this process is another form of beta decay, called beta-plus decay (β+ decay).

Upon encountering an electron, a positron will annihilate it, resulting in the production of gamma radiation. This annihilation concept finds application in medical imaging techniques such as Positron Emission Tomography (PET), which is used to observe metabolic processes in the body for diagnostics.

Gamma rays are a form of electromagnetic radiation, similar to X-rays, visible light, and radio waves. They are denoted by the Greek letter γ. Gamma rays carry the highest energy per photon among other types of electromagnetic waves and are thus capable of penetrating through most types of materials, including human tissue.

Gamma rays originate from the atomic nucleus and are often produced during nuclear reactions, such as the decay of radioactive isotopes or in nuclear explosions. They can also be emitted by astronomical phenomena such as supernovae. Due to their penetrating power and energy, gamma rays are used in cancer treatment to kill cancerous cells but require careful handling because they can pose significant health risks if not properly contained and directed.