Question

assume the diameer of a neutral helium atom is 1.40 x 10 to the second power pm. suppose that we could line up helium atoms side by side in contact with one another. how many atoms would it take to make the distance from end to end 9.00cm

Answer 1

1.4E2 pm = 140 pm
140 pm x (1 m/1E12 pm) x (100 cm/m) = ?? cm diameter.

?? cm x # atoms = 9 cm.
Solve for # atoms.