Final answer:
Subatomic particles with a positive charge are called protons, which are fundamental building blocks of the atom's nucleus and contribute to its positive charge.
Step-by-step explanation:
Subatomic particles with a positive charge are known as protons. These particles are fundamental components of the atom's nucleus, which gives the nucleus its positive charge. Protons, along with neutrons and electrons, are the three fundamental building blocks of most matter. While electrons carry a negative charge, protons carry a positive charge, which is considered a fundamental property of these subatomic particles. The charge-to-mass ratio of a proton is approximately 9.57 × 107 C/kg. Though there are other charge-carrying particles observed in cosmic rays, nuclear decay, and created in particle accelerators, they are usually short-lived and rare compared to protons and electrons. The presence of protons in the nucleus and the electrons orbiting around it create the basic structure of the atom as depicted in atomic models.