Utah Master Esthetician Practice Exam

What makes up the nucleus of an atom?

1. Electrons and neutrons

2. Protons and neutrons

3. Protons and electrons

4. Electrons and quarks

The correct answer is: Protons and neutrons

The nucleus of an atom is composed of protons and neutrons. Protons are positively charged particles, while neutrons are neutral, meaning they have no charge. These two types of particles are found in the dense center of the atom, which is crucial in determining the atom’s mass and overall identity. The number of protons in the nucleus defines the element (for example, hydrogen has one proton, while carbon has six), and the neutrons contribute to the atomic mass and can affect the stability of the nucleus. Other options mention electrons or quarks, which do not belong in the nucleus. Electrons are negatively charged particles that orbit the nucleus and are involved in chemical bonding and reactions, but they do not reside within the nucleus itself. Quarks, on the other hand, are fundamental particles that combine to form protons and neutrons but are not considered constituents of the atomic nucleus in this context. Thus, protons and neutrons are the correct components that make up the nucleus.