Final answer:
The incorrect statement is 'The mass of an α particle is 7300 × that of the electron'. An α particle's mass is about 4 amu, which is much more massive than an electron but is not quantified by the exact number 7300.
Step-by-step explanation:
The statement 'The mass of an α particle is 7300 × that of the electron' is not correct. An α particle, or alpha particle, has a mass approximately 4 atomic mass units (amu), which is roughly 7,300 times the mass of an electron, but the comparison is between the mass of the helium nucleus (alpha particle) and the electron, not directly translating to the number 7300 as a multiplier. On the other hand, statements 'An α particle has a 2+ charge', 'Three types of radioactive emission are γ rays, β rays, and α particles', and 'A γ ray is high-energy light' are all correct. An alpha particle is indeed composed of two protons and two neutrons, which gives it a 2+ charge. Also, the three types of radioactive emissions are alpha particles, beta particles, and gamma rays. Gamma rays are a form of electromagnetic radiation with very high energy, often associated with radioactive decay processes.