MCQ Detailed View

Radioactive elements emit different types of particles during radioactive decay. The particle that carries a positive charge is called an alpha particle, also referred to as alpha rays. Alpha particles consist of two protons and two neutrons, which is essentially a helium nucleus (He²⁺). Because of the two protons, alpha particles have a +2 positive charge, making them positively charged radiation.

In contrast, beta rays are streams of electrons or positrons. A beta-minus particle carries a negative charge, while a beta-plus particle (positron) carries a positive charge but is different from an alpha particle in mass and composition. Gamma rays are electromagnetic radiation and carry no charge at all.

Alpha particles are relatively heavy and slow-moving compared to beta and gamma radiation. They have low penetration power, meaning they can be stopped by a sheet of paper or even the outer layer of human skin. However, they are highly ionizing, meaning they can cause significant damage if radioactive material emitting alpha particles is ingested or inhaled.

Alpha decay is commonly observed in heavy radioactive elements such as uranium-238, radium-226, and thorium-232. During alpha decay, the parent nucleus loses two protons and two neutrons, transforming into a different element and releasing an alpha particle. This process helps reduce the atomic number and mass number of the unstable nucleus, leading to more stable isotopes.

Understanding the properties of alpha particles is fundamental in nuclear physics, radiation safety, and environmental science, as it explains the behavior of radioactive substances and how radiation interacts with matter. It also forms the basis for studying radioactive decay series and applications in medical treatments, nuclear energy, and scientific research.