//example-17.3
//page no-515
//given
//atomic weight  and density of magnesium
MMg=24.3  //gm
rhoMg=1.740  //g/cm^3
//molecular weight and density of MgO
MMgO=40.3  //gm
rhoMgO=3.650  //g/cm^3
//volume of Mg and Mgo
VMg=MMg/rhoMg  //cm^3
VMgO=MMgO/rhoMgO  //cm^3
//we know that pilling-bedworth ratio is given by
PBR=VMgO/VMg  
printf ("since PBR is less than 1 so the film formed is not protective ")