The magnetic field imparts little force on the relatively heavy and slow moving positive ions but has {TAIL ~ a significant impact} on {HEAD ~ the relatively fast moving, light weight electrons} 
The magnetic field imparts little force on the relatively heavy and slow moving positive ions but has { TAIL ~ a significant impact } on { HEAD ~ the relatively fast moving , light weight electrons }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD