mass spectra (singular: mass spectrum singular)
Is a record of the chemical constituent of a substance separated according to their mass and presented as a spectrum as measured using a mass spectrometer. One of these versions of this device is known as a bainbridge mass spectrometer. At this instrumental operate on the principle that a beam of iron is made to pass through a velocity selector. in the velocity, selected a charged particle or move with the same velocity. This is gain by a combinations of vertical downward electric field that is perpendicular to a magnetic field in the velocity selector the magnetic force which is qv x B and the electric field which is E when the charged particles move in the straight horizontal line to the field the magnetic force is equal to the electric field I.e qvV = qE
V = E/B
The charged particles from the velocity selector enter the second magnetic field Bo that has the same direction as velocity selector. Upon entering the second magnetic field that move in semi circle of radius r before striking the photographic plate. If the ions are positively charged the beam deflect upward and if the iron and negatively charged the beam deflects downward. while is circular motion the centripetal force F = mv²/r force is equal to the magnetic force (qvB0)
I.e mv²/r = B0qv
Mv/r = B0q
m/q = B0r/v
But v = E/B
m/q = B0rB/E
Therefore we can determine m/q by measuring the radius r of the curvature and knowing the field B, B0, and E. Importantly, the mass spectrometer measured the various isotope of a given iron since they are all carry the same charge q. In this way the mass ratios can be determined even if q is unknown.
Isotope element with unequal mass number but equal atomic number or they have the same atomic number but different nature number.