Answer:
Explanation:
A truckload of pennies is quite a very large amount of problem to solve. A truck can carry a lot of coins which can be up to several millions in number approximately.
This is similar to counting the number of atoms in 10.0g of aluminium.
In a mole of any substance, there are 6.02 x 10²³ atoms.
number of moles = 
molar mass of Al = 27g/mole
number of moles =
= 0.37moles
Number of atoms = 0.37 x 6.02 x 10²³ = 2.23 x 10²³ atoms
In 10g of aluminium, there are 2.23 x 10²³ atoms. It is even much more tedious to count.
Difference;
We can see the pennies in the truckload. They are discrete. It is impossible to see atoms in a substance this way.
Also, the number of atoms in 10g of aluminium is more than that of pennies in a truckload.