If the diameter of a carbon is 0.15 nm, calculate the number of carbon atoms which can be placed side by side in a straight line across the length of scale of length 20 cm long. 


Correct option is


Diameter of carbon atom = 0.15 nm  

                                         = 0.15 × 10–9 m  

                                         = 1.5 × 10–10 m  

Length along which atoms are to be placed = 20 cm  

                                                                      = 20 × 10–2 m 

                                                                      = 2 × 10–1 m  

∴ No. of C-atom which can be placed along the length




× 108 atoms of carbon are arranged side by side. Calculate the radius of carbon atoms if the length of this arrangement is 3.0 cm.


The diameter of zinc atom is 2.6 Å. Calculate number of atoms present in a length of 1.6 cm if the atoms are arranged side by side lengthwise.