Question

Figure 5 shows a radioactive element placed in an evacuated glass chamber. The element produces alpha, beta and gamma emissions.

The three emissions pass through an electric field.

1. Complete the diagram to show the path of each of the emissions. 
2. State the reason why:
   • the radioactive element is kept inside a lead box: 
   • the chamber is evacuated

Answer 1

1.   
   
   Deflected earlier and moves further
   Deflected later and doesn't move further
2.    
   • To shield the radiation from moving to the other direction
   • Prevent collision of clear vision on the effect of the field/ minimise loss of / prevent ionisation