GED Science Practice 2026 – 400 Free Practice Questions to Pass the Exam

The chosen answer highlights that a proton is a stable subatomic particle that carries a positive charge. Protons are essential components of atomic nuclei, and their positive charge contributes to the overall positive charge of an atom’s nucleus, which is balanced by negatively charged electrons that orbit around it. This stability and charge are fundamental properties that define not only protons but also play a crucial role in the structure of matter.

In understanding why this characteristic is central to defining a proton, it's worth noting how protons interact with other particles and their significance in atomic structure and chemistry. For example, the number of protons in an atom determines its atomic number and, consequently, its identity as a specific element.

In contrast, the other options do not accurately characterize a proton:

- The reference to celestial bodies relates to astrophysical concepts rather than particle physics.

- Providing oxygen and nutrients to a fetus pertains to biological functions and is unrelated to protons or atomic science.

- The synthesis of compounds with radiant energy involves chemical processes and energy transformations rather than the inherent properties of protons.

Overall, recognizing a proton as a stable particle with a positive charge encapsulates its critical role in the foundation of atomic and molecular structures in science.