Question

The atomic radius of zinc is 125 pm (1 pm = 1 x 10-12 m). This process puts a layer of zinc about 50 nm think (1 nm = 1 x 10-9 m) on the penny.
a. Calculate the thickness of the zinc layer in atoms (assume they line up in a straight line) (hint radius, diameter).
b. Find the area of a penny in cm2. (A = πr2 and there are two sides to the penny- we’ll ignore the edges).
c. Multiple the height of the zinc layer (convert it to cm)by the area in cm2 and you’ll get the volume in cm3 (ml).
d. Look up the density of zinc and combine that with the volume of deposited zinc to get the number of g

Answer 1

Just use regular math/geometry concepts

for example, for the first question you have

So the diameter is 2*125 pm, and the thickness of the layer is 50 times the diameter.

Answer 2

wait i read the question wrong, divide the diameter by 50 nm to find the thickness of the layer in terms of atoms.