Me : )) 15 points (chemistry)
define substance and give two examples of things that are substances

Determine the mass of fuel required for the expected energy consumption in the united states for the next ten years. energy use per person per year in the united states = 3.5 x 1011joules base calculations on current population of 310,000,000.

Why is permeable soil best for plants that need a lot of drainage?

Particles vibrate in a rigid structure and do not move relative to their neighbors.