Asian Journal of Research and Reviews in Physics <p style="text-align: justify;"><strong>Asian Journal of Research and Reviews in Physics (ISSN: 2582-5992)</strong> aims to publish high-quality papers in all areas of 'physics'. The journal also encourages the submission of useful reports of negative results. This is a quality controlled, OPEN peer-reviewed, open access INTERNATIONAL journal.</p> SCIENCEDOMAIN international en-US Asian Journal of Research and Reviews in Physics 2582-5992 Theoretical Determination of the Mass Radii of the Nucleons and Heavier Subatomic Particles <p><strong>Background: </strong>The literature contains numerous values of nucleon charge radii with greater interest in proton. The mean square negative radii are reported for the neutron, the scientific relevance notwithstanding. Only in very few instances was the mass radius of the nucleon investigated.</p> <p><strong>Methods: </strong>Theoretical and computational methods.</p> <p><strong>Objectives: </strong>The objectives of this research are to derive, based mainly on classical model, the equation of the radii of nucleons and other subatomic particles heavier than the nucleons and determine by calculation based on the equation the radii of such particles, and elucidate why results may be different from literature values.</p> <p><strong>Results and Discussion: </strong>The results showed expectedly that the mass radii of nucleons and heavier subatomic particles are longer than what seemed to be the preferred proton charge radius. The lengths of the calculated radii increase with increase in rest mass of the subatomic particles whose mass must be ³ the mass of any nucleon</p> <p><strong>Conclusion: </strong>The equation of the mass radius of any nucleon and heavier subatomic particles was derived. Expectedly, the radii differ on the basis of differences in masses of the particles. The difference in mass radii as calculated in this research and reported charge radii in the literature may be due to electron capture leading to greater number of elastic collision with resulting neutrons. Two particles of widely different mass possessing different charge must interact attractively or repulsively if they possess similar charges. Otherwise the deflection of beta–rays and similar particles in an electromagnetic field would be impossible.</p> Ikechukwu I. Udema ##submission.copyrightStatement## 2020-09-07 2020-09-07 1 10 10.9734/ajr2p/2020/v3i430125