{HEAD ~ The typical particle size} is from {TAIL ~ about 0.7 to about 0.8 micrometers} in mean diameter 
is from
{ HEAD ~ The typical particle size } is from { TAIL ~ about 0.7 to about 0.8 micrometers } in mean diameter
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH