Question

The radius of an aluminum atom is 0.125 nm. How many aluminum atoms would have to be lined up in a row as shown below to form a line 5.00 cm in length?

Answer 1

Solution :-

radius of aluminum = 0.125 nm

distance = 5.00 cm

lets convert the 0.125 nm to cm

0.125 nm * 1*10^-7 cm / 1 nm = 1.25*10^-8 cm

when atoms are lined up then we have to use thier diameter

diameter d= r*2

so

number of atoms = 5.00 cm / (1.25*10^-8 cm * 2)

                         = 2.00*10^8 atoms

So it needs 2.00*10^8 atoms of Aluminum.