International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

What type of particles are protons and neutrons classified as?

1. Electrons

2. Nucleons

3. Quarks

4. Positrons

The correct answer is: Nucleons

Protons and neutrons are classified as nucleons because they are the particles that make up the nucleus of an atom. The term "nucleon" encompasses both protons, which have a positive charge, and neutrons, which are neutral particles. These particles play a crucial role in determining the atomic mass and the stability of the nucleus, as they are held together by the strong nuclear force. In contrast, electrons are a different type of subatomic particle that orbit the nucleus and carry a negative charge. Quarks are even smaller particles that combine to form protons and neutrons; while each proton and neutron is made up of a combination of quarks, the term "nucleon" specifically refers to the whole particles rather than the individual components. Positrons are the antiparticles of electrons, carrying a positive charge, and are generally not part of the atomic nucleus. In summary, protons and neutrons, being integral components of the nucleus, are correctly identified as nucleons in the context of atomic structure.