The earliest artificial radioactive substance was produced by striking aluminium, $^{27}_{13}\text{Al}$, with $\alpha$-particles. As a result, an unstable phosphorus isotope, $^{30}_{15}\text{P}$, was formed. What was the other product of this reaction?
- Aan $\alpha$-particle
- Ba $\beta$-particle
- Ca $\gamma$-ray
- Da neutron