Summary EDEXCEL A-LEVEL CHEMISTRY REVISION NOTES: ATOMIC STRUCTURE

,
, -Atomic Structure
Structure ofAn Atom

Proton -
Relative mass ofI-relative charge of +1


N eutron -


Relative mass of 1 -

relative charge ofO


Electron -

Relative mass of1836 -

relative charge of -1



Atoms consistofa central nucleus containing provous and neutrons.
The nucleus is ring compared to the whole size of the atom. It
Is surrounded by electrons in energy levels called shells. Atoms
have no electric charge because they have the same number of
protons and electrons



Atomic Number no.
=
of
protons


Mass Number no.
=


protons
of no.
+
of neutrons



Relative Atomic Mass -



the weighted average mass ofan atom of an
elementrelative to viz of the mass ofthe isotope carbon-12

Relative Isotopic mass
-
the mass of an isotope of an element relative
to iiz ofthe mass of the isotope carbon-12




Relative Atomic Mass- mass no. Ax v.) -
mass no exv.
100




Mass Spectrometry

1) vapourisation -


Sample injected:becomes a gas


2) conisation -
bombarded by electrons:makes five long


3) Acceleration -
all ions enter magnetic field atsame velocity

4) Separation -
magnetic field deflects ions in vacuum

5)Detection -
Ions detected and recorded electronically