Answer with Step-by-step explanation:
Since 1 mole of sand will contain Avagadro's Number of sand particles (by definition of 1 mole)
Thus we have
1 mole of sand =
sand particles
Thus in number of trillion sand particles we have no of trillion sand particles in 12 mole is

Now since it is given that mass of 1 trillion sand particles is 1000 tonnes Thus the mass of
trillion sand particles is

Part 2)
Since it is given that volume of 1 sand particle is
thus the volume of 1 mole of sand is volume of
sand particles
Thus volume of 1 mole is

Now since the Area of united states is

Thus the depth of the sand pile is
