Answer:
a)It will be deeper b. It will be prettier
Step-by-step explanation:
Interaction volume depends on the following parameters
1.Material parameter
2.Till angle
3.Beam energy
Interaction volume is also known as beam range and beam range given as follows

Where Eo is energy
A is atomic weight
ρ is density
Z is atomic number

When Z decreases then R will increases it means that interaction volume will be deeper.