Isotopes and mass spectrometry Tamil revision mind map presented as a four-stage instrument flow: ionisation of a vaporised sample, acceleration through an electric field, deflection in a magnetic field proportional to mass, and detection producing a mass spectrum, defining atomic number mass number and neutron number, explaining isotopes as same-element atoms differing only in neutron count with near-identical chemistry but different physical properties, and a worked weighted-average relative atomic mass calculation for chlorine from its two isotopes.