ASNT Radiographic Testing Practice Test 2025 – Comprehensive All-in-One Guide for Exam Success!

Particles that possess a positive or negative charge are known as ions. This occurs when atoms gain or lose electrons, resulting in an imbalance between protons (which carry a positive charge) and electrons (which carry a negative charge). If an atom loses one or more electrons, it becomes a positively charged ion, also referred to as a cation. Conversely, if an atom gains electrons, it becomes a negatively charged ion, known as an anion.

Understanding ions is essential in various fields, including chemistry and physics, as they play critical roles in reactions, electrical conductivity, and the formation of compounds. In contrast, atoms refer to the basic units of matter and can be neutral, having an equal number of protons and electrons. Molecules consist of two or more atoms bonded together and may also be neutral. Free radicals are unstable atoms or molecules that have unpaired electrons, which can lead to chemical reactions but do not inherently denote a positive or negative charge.