Answer:
Step-by-step explanation:
People use detector to know the ionization of electromagnetic radiation i.e alpha, beta and gamma radiation and the output produced.
In the past, the early detectors use photographic plates which is use to detect tracks due to nuclear reactions.
It is important to know particles before inventing detectors because detectors produces visible trajectories or tracks as a result of particles that are charged which can traverse the apparatus. It was used to detect the positron and also muons and these w are particles that are produced by cosmic rays which is as a result of their interaction in the Earth's atmosphere.