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Particle Charge Mass
Proton +1 1
Neutron 0 1
Electron -1 1/1863
Atomic Structure:
In nucleus ­ protons & neutrons (AKA nucleons)
In outer shells ­ electrons
This therefore means that the atom is neutral
Number of protons = Number of neutrons
Atomic and Mass number:
Mass number ­ Number of nucleons
Atomic number ­ Number of protons
These are atoms with the same atomic number but different mass
number (more neutrons)
2412Mg - 12 protons, 12 neutrons
2512Mg - 12 protons,…read more

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The four stages:
Prepare the sample
Vaporise the sample: put the sample into low pressure and boil
to turn sample into a gas
Inject the sample into the Mass Spectrometer
Mass spectrometer requires a vacuum to prevent air
molecules from hitting the ions
Stage 1: Ionisation
Particles within the atom are hit by an electron gun within the
ionisation chamber
This knocks electrons off the atom and therefore ionises it
to a +1 ion.…read more

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Stage 2: Acceleration
The positively charged ions are attracted to negatively
charged plates causing them to accelerate
Stage 3: Deflection
Ions need to be deflected by magnetic fields in order to get
to the detector.
The heavier the ion, the less the deflection
Just right
Too light
Too heavy
Stage 4: Detection
The electric current measured as ions land on the plate.
You can get a different sample of ions by altering the
strength of the magnetic field during Stage 3.…read more

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The greater the number of particles landing at a single point on
the detector, the greater the electric current and the larger
the peak.
Using Mass Spectrometry to find out the Relative Atomic Mass
(Mean mass of an atom / mass of one atom)
Eg: Neon
(90 x 20) + (10 x 22) = 20.2 Mr (always to 1 d.…read more

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Each shell must be filled up before proceeding to the next shell
starting at 1s.
When the 3p level is full, you start on the 4s level rather than
the 3d level.
Although the 4s shell gets filled before the 3d shell, while
writing it, the 3d shell must go first.…read more

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As you go down a group, the number of shells increases. This
means the electrons are further away from the shell due to a
larger atomic radius which means less nuclear attraction.
Therefore the further down you get in a group, the easier an
electron is to be removed.
There is also more electrons shielding due to more electrons
being in the way of the proton trying to attract electrons. This
means there is less of a nuclear attraction.…read more


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