radiation

• alpha has 2 protons and 2 neutrons
• alpha is least penetrating, can be stopped by paper
• alpha travels a few cm
• beta is a fast moving electron
• beta can penetrate air and paper, but stopped by thin aluminium
• beta can travel 10s of cm
• gamma is electromagnetic radiation
• gamma is most penetrating as penetrates paper, air and thin metal
• gamma is stopped by lead or a metre of concrete
• gamma travels large distacnes