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Chem Wk1 - Coggle Diagram
Chem Wk1
Mass spectrometry
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Produces graph called mass spectrum, plot of the measured abundance of each isotope against mass charge ratio
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- vaporisation 2. ionisation 3. acceleration 4. deflection 5. detection
mass spectrometry involves the ionisation of substances and the seperation and detection of the resulting ions
the spectra which are generated can be analysed to determine isotopic composition and interpret to determine relative atomic mass
if charge same, lower mass= greated degree of deflection
if mass same, higher charge= greater degree of deflection
sample, ionisation chamber, filament to provide bombarding electrons, charge plates to provide electrical field, magnetic field at right angles, ion collector, detector to measure ion current.
History of the atom
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Democritus
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dif subs had atomos of dif shapes, sizes, and properties
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JJ Tomson
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particles flow -ve to +ve, and are replled by another -ve electrode
therefore -ve charged particle present in all atoms, and a +ve particle to balance charges
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E Rutherford
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most passed through, some deflected
therefore most of atom empty space, most mass in centre NUCLEUS
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Isotopes
same number of protons as an atom of that element, but different number of neutrons
similar chemical properties (because same number of electrons), but different physical properties (because dif neutrons/mass number)
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relative atomic mass= weighted average of relative isotopic masses taking into account their abundance in nature
relative isotopic mass= the mass of the isotope on a scale on which a carbon-12 atom has a mass of exactly 12 units.
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chemical properties= only seen when chemical reaction occurs (e.g. flammibility, acidity)
physical property= does not change as you are measuring it. (e.g. melting point, density, mass)
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