The % pore space in a soil having a bulk density of 1.16 mg m^-3 and particle density of 2.62 mg m^-3 is

The space between the soil particles in the pore space.
The formulas for calculating the pore space percentage $${\text{PS}} = \left( {1 - \frac{{{\text{BD}}}}{{{\text{PD}}}}} \right) \times 100$$
where PS is Pore Space, BD is Bulk Density and PD is Particle Density.
Putting all the values in the above formula
$${\text{PS}} = \left( {1 - \frac{{1.16}}{{2.62}}} \right) \times 100 = 0.557 \times 100 = 55.7\% $$