Question

Write the symbols used to denote alpha, beta, and gamma radiation and give their mass and charge.

Short answer

The symbols for alpha, beta, and gamma radiation are \(\alpha\), \(\beta^-\) (for electrons), \(\beta^+\) (for positrons), and \(\gamma\), respectively. For alpha radiation, the mass number is 4 and the charge is +2. For beta radiation, the mass number is approximately 1/1836, with a charge of -1 for electrons and +1 for positrons. Gamma radiation has no mass or charge.

Step-by-step solution

Alpha Radiation

Alpha radiation is composed of alpha particles, which are made up of 2 protons and 2 neutrons. To denote alpha radiation, we use the symbol \(\alpha\) or the symbol \(_{2}^{4}\textrm{He}\), as each alpha particle is essentially the same as a helium-4 nucleus. The mass number of an alpha particle is 4 (2 protons and 2 neutrons), and the charge is +2 (2 protons with a charge of +1 each).

Beta Radiation

Beta radiation consists of beta particles, which are high-energy electrons (\(\beta^-\)) or positrons (\(\beta^+\)). Beta particles are denoted by the symbols \(\beta^-\) for electrons and \(\beta^+\) for positrons. The mass number of a beta particle is approximately 1/1836 (as electrons or positrons are much lighter than protons or neutrons), and the charge is -1 for electrons (\(\beta^-\)) and +1 for positrons (\(\beta^+\)).

Gamma Radiation

Gamma radiation is composed of gamma rays, which are high-energy electromagnetic waves. They do not have any mass or charge. Gamma rays are denoted by the symbol \(\gamma\). In summary: - Alpha radiation (\(\alpha\)) has a mass number of 4 and a charge of +2. - Beta radiation (\(\beta^-\) and \(\beta^+\)) has a mass number of approximately 1/1836 and charges of -1 and +1, respectively. - Gamma radiation (\(\gamma\)) has no mass or charge.

Key concepts

Alpha Radiation

Alpha radiation is a type of nuclear radiation that involves alpha particles. These particles are quite massive in comparison to other forms of radiation. They are essentially the nucleus of a helium-4 atom, consisting of 2 protons and 2 neutrons. This composition gives alpha particles their symbol \(\alpha\), or alternatively \(_{2}^{4}\text{He}\).

Due to their mass, alpha particles have a significant charge of +2. This is because each proton in the particle has a charge of +1. However, it's important to note that their larger mass relative to other particles, like beta particles, limits their penetrating ability. Alpha particles can be stopped by something as thin as a sheet of paper or even the outer layer of human skin.

When dealing with alpha radiation, safety measures often focus on making sure there is no direct exposure or inhalation, as alpha particles can cause serious damage if they enter the body.

Beta Radiation

Beta radiation is made up of beta particles, which are much lighter than alpha particles. They are either high-energy electrons (\(\beta^-\)) or their positive counterparts, positrons (\(\beta^+\)). The symbols used for these particles are \(\beta^-\) and \(\beta^+\) respectively.

The mass of a beta particle is minuscule, approximately 1/1836 that of a proton or neutron. This allows beta particles to travel further than alpha particles. However, despite their energy, beta particles have relatively low mass, giving them a charge of -1 for electrons and +1 for positrons.

Beta radiation can penetrate materials more effectively than alpha radiation, but it can still be halted by materials like plastic or glass. In safety procedures, a common precaution is to use shields like plexiglass to protect against this type of radiation while ensuring that there are no direct paths to the body to prevent deep tissue penetration.

Gamma Radiation

Gamma radiation differs significantly from alpha and beta radiation as it is not composed of particles with mass. Instead, gamma rays are high-energy electromagnetic waves. With no mass or charge, gamma rays are denoted by the symbol \(\gamma\).

The lack of mass and charge allows gamma rays to penetrate materials more deeply than alpha or beta particles. This high penetration ability requires significant protection when dealing with gamma radiation, typically using dense materials like lead or concrete.

Because of their deep penetrative power, gamma rays are frequently used in medical treatments, such as in the case of radiotherapy, while also posing the potential for significant damage if not carefully controlled in both medical and industrial settings. Ensuring proper shielding and exposure time are critical to maintaining safety when working with or near sources of gamma radiation.