Same number of protons, different number of neutrons
React the same chemically
Vary in mass number
Mass Spectrometer
1. Gaseous state
2. Ionisation - beam of electrons from an electron gun knocks electrons to make positive ions
3. Acceleration - positive ions are attracted towards negatively charged plates and are accelerated the lighter the ions the faster they go , they pass through slits in the plates forming a beam
4. Deflection - beam moves into a magnetic field which deflects them into an arc (m/z dependant) heavier ions are deflected less
5. Detection - magnetic field is gradually increased so ions with increasing mass enter the detector creating a current proportional to their abundance
Electron arrangement
1S, 2S, 2P, 3S, 3P, 3D, 4S etc
2 electrons in s orbital, 6 in p orbital, 10 in d orbital and 14 in f orbital
Ionisation energy
the energy required to remove one mole of electrons from one mole of atoms in the gaseous state
General increace across periods because nuclear charge increaces
decreace down periods because the outer electron is further away from the nucleus