(a)[3]
Explain how the helium particles create this pressure.
(b(i))[1]
State an equation linking the helium volume with its pressure.
(b(ii)-1)[2]
Using Fig. 6.2, find the pressure at ground level. Include the unit.
(b(ii)-2)[2]
Using Fig. 6.2, find the height where the helium in the balloon has doubled in volume compared with ground level.