There are three kinds of nuclear radiation. Alpha is a slow, heavy, strongly charged particle that is easily stopped. Beta is a fast electron that gets a bit further. Gamma is a high-energy wave that is very hard to stop. Thicken the absorber from nothing, to paper, to aluminium, to lead, and watch which radiations still reach the detector.
MissionChoose the absorber so the right radiations reach the detector.Round 1Streak 0Best 0
Compared with what the mission needs, this absorber:
The source is always emitting. Slide the absorber, predict, then check the detector.
alpha (helium nucleus, +2)reaches
beta (fast electron, -1)reaches
gamma (EM wave, no charge)reaches
Most ionising is least penetrating: alpha stopped by paper, beta by aluminium, gamma only reduced by lead.