Science Pls help me with number 9 and 10

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 carbon ideal for making different compounds?

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?