Paper thickness varies. typically, 100 sheets are about a cm thick. atoms typically vary from 1 to 3 angstroms in radius. (an angstrom is 10-10 m.) suppose a piece of paper is 0.0084 cm thick. how many atoms span the thickness if the radius of the atom is 2.97 angstroms?

#atoms = 141414.1414 ...

Explanation:

''Suppose a piece of paper is 0.0084 cm thick'' this means that paper thickness = 0.0084 cm

0.0084 cm = 0.000084 m  

Now that we changed the unit from cm to m let's write the following statement

#atoms = paper thickness/atoms diameter

''If the radius of the atom is 2.97 angstroms'' so atom radius = 2.97 angstroms

diameter = 2.radius = 2 x 2.97 angstroms = 5.94 angstroms

Finally,

#atoms = paper thickness/atoms diameter

#atoms = 0.000084 m / 5.94 angstroms

1 angstroms = 10^(-10) m

#atoms = 0.000084 m / 5.94 . 10^(-10) m

#atoms = 141414.1414 ...

Notice that there is an important difference between the atom diameter and the atom radius. That is the key to solve this problem