"why finding the q/m requires equating F=qvb=mv[squared]/r (centrepital force?? this part i dont get)"
he equated F=qvb=mv²\r to obtain the equation for q/m:
qvb=mv²\r
qb=mv\r
q\m=v\br
he used this centripetal force equation because the charge in the magnetic field alone would go in a curve path
"whats the big deal about q/m ratios?? "
the ratio had important implications for theories of atoms.
thomson found that ALL CATHODE RAYS HAD THE SAME q/m ratio
this value was 1800 times greater than the ratio obtained for hydrogen ions, hence he concluded that the mass of cathode rays is 1\1800 the mass of hydrogen ion.
den also he concluded that CATHODE RAYS ARE A CONSTITUENT OF ALL ATOMS, so now we know that cathode rays are infact electrons.
anyone feel free to add anything or correct anything if im wrong
