Estimate the number of crystal-like spherical clusters containing a) 15 atoms and b) 25 atoms in 1mm3 of liquid copper at 1306K. The atomic volume of liquid copper () is 1.61029m3, solid-liquid interface energy (YsL) is 0.177J/m2, k=1.381023J/K,Tm=1356K. The enthalpy of melting of Cu is 13.05kJ/ mole