Supply a complete symbol, with superscript and subscript, for each of the following types of radiation. a. Alpha particle b. Beta particle c. Gamma ray
The correct answer and explanation is :
a. Alpha particle
Symbol: (_{2}^{4}\text{He}) or (_{2}^{4}\alpha)
b. Beta particle
Symbol: (_{-1}^{0}\text{e}) or (_{-1}^{0}\beta)
c. Gamma ray
Symbol: (_{0}^{0}\gamma)
Explanation (Approx. 300 words):
Radiation in nuclear chemistry typically refers to particles or energy released during radioactive decay. Each type of radiation can be described using nuclear notation, which includes the mass number (superscript) and atomic number (subscript).
Alpha particles are helium nuclei consisting of two protons and two neutrons. They have a mass number of 4 (2 protons + 2 neutrons) and an atomic number of 2 (representing 2 protons). This makes the complete nuclear symbol for an alpha particle (_{2}^{4}\text{He}) or more commonly (_{2}^{4}\alpha). Because of their relatively large mass and charge, alpha particles have low penetration power and can be stopped by a sheet of paper or even skin.
Beta particles are high-energy, high-speed electrons or positrons emitted from a nucleus during radioactive decay. In beta-minus (β⁻) decay, a neutron converts into a proton, emitting an electron. Since electrons are not made of nucleons (protons or neutrons), their mass number is 0, and their atomic number is -1 to represent the negative charge. Thus, the symbol is (_{-1}^{0}\text{e}) or (_{-1}^{0}\beta). Beta particles are more penetrating than alpha particles but can still be stopped by materials like plastic or aluminum.
Gamma rays are not particles but electromagnetic radiation emitted from an excited nucleus returning to its ground state. They carry no mass or charge, so both the mass number and atomic number are 0. This is denoted as (_{0}^{0}\gamma). Gamma rays have high penetration power and require dense materials like lead or several inches of concrete to block them.
These symbols are essential in understanding and balancing nuclear reactions in physics and chemistry.
