Conquer the CLEP Chemistry Challenge 2025 – Unleash Your Inner Scientist!

An alpha particle is best described as 4/2 He. This notation represents a helium nucleus consisting of two protons and two neutrons, giving it a total mass number of 4 and an atomic number of 2. Alpha particles are emitted during radioactive decay processes, specifically from heavy elements like uranium and radium, as they seek stability through the loss of these massive particles.

The structure of an alpha particle is significant because its positive charge and relatively large mass contribute to its behavior in various nuclear reactions. When an alpha particle is emitted, the original atom transforms into a new element with a reduced mass and atomic number, leading to changes in its properties.

The other choices represent different types of particles. The notation 0/-1e refers to a beta particle (an electron), and 0/+1e represents a positron, which is the antimatter counterpart of an electron. The notation 1/0 n indicates a neutron, which, while being a nucleon, does not carry a charge and is not involved in the type of decay characterized by the emission of alpha particles.