To identify the type of radiation that has the same mass as an electron but a positive charge, we need to evaluate each option:
a. [tex]\(\gamma\)[/tex] - Gamma radiation ([tex]\(\gamma\)[/tex]) consists of high-energy photons. These photons have no mass and no charge. Hence, [tex]\(\gamma\)[/tex] does not match the criteria.
b. [tex]\(\beta-\)[/tex] - Beta-minus radiation ([tex]\(\beta-\)[/tex]) represents an electron emitted from a nucleus. Electrons have a negative charge. Thus, [tex]\(\beta-\)[/tex] does not match the criteria either.
c. [tex]\(\alpha\)[/tex] - Alpha radiation ([tex]\(\alpha\)[/tex]) consists of helium nuclei, which include two protons and two neutrons. This type of radiation has substantial mass (significantly greater than that of an electron) and a positive charge. However, its mass is much larger than that of an electron, so [tex]\(\alpha\)[/tex] does not fit the criteria.
d. [tex]\(\beta+\)[/tex] - Beta-plus radiation ([tex]\(\beta+\)[/tex]), or positron emission, involves the emission of a positron from the nucleus. A positron has the same mass as an electron but carries a positive charge, which matches the required properties exactly.
Considering these explanations, the correct answer is:
d. [tex]\(\beta+\)[/tex] (positron)
