The length covered by 1 carbon atom corresponds to its diameter. The diameter of carbon atom is $$displaystyle rac {2.4}{2 imes 10^{8}}=1.2 imes 10^{-8  } $$ cm. The radius of carbon atom is $$displaystyle rac {1.2 imes 10^{-8} }{2} = 0.6 imes 10^{-8} cm =0.06 nm $$.