ASNT Industrial Radiography Radiation Safety Practice Test

What is the center of an atom commonly referred to as?

1. Electron

2. Neutron

3. Nucleus

4. Proton

The correct answer is: Nucleus

The center of an atom is commonly referred to as the nucleus. The nucleus is a dense region that contains most of the atom's mass and is made up of protons and neutrons. The protons carry a positive charge, while the neutrons are neutral. Together, they determine the atomic number and the mass of the atom. Understanding the role of the nucleus is fundamental in the study of atomic structure and radiological safety, as it is involved in various interactions such as radioactive decay and nuclear reactions, which are essential topics in industrial radiography and radiation safety. The nucleus is distinct from electrons, which orbit around the nucleus and comprise a much smaller part of the atom's mass.