Real-Life Math
Understanding the density of pore spaces (air pockets) in soil is very important for soil scientists. Too great a percentage of pore space will mean the soil can be easily washed away; too few pore spaces means the soil won't absorb nutrients.
Figuring out pore density involves a complicated formula. First, you have to figure out the bulk density and particle density.
Bulk density = weight of soil sample / natural volume (size) of soil sample
Particle density = weight of soil sample / compressed volume (size if you squished the soil together) of soil sample
You want to determine the percentage of pore space in your soil sample. To do that, you need to know what percentage of your sample is soil solids.
Percent of soil solids = bulk density / particle density x 100
Percent of pore space = 100 - percent of soil solids
The natural volume of your soil sample is 1 square centimeter. The compressed volume of your soil sample is 0.55 square centimeters. The weight of your soil sample is 1.5 grams.
Using the formula above, determine the percentage of pore space in this soil sample.