1.2. electronic shells Flashcards
what was the theory about electronic shells
electrons have fixed shell energy shells. each shell is given a number called the principal quantum number. the further the shell is to the nucleus the higher the principal quantum number
what do experiments show
they show that bot all the elctrons in a shell have exactly the same energy. the atomic model shows that shells are split u into sub-shells. different shells have different numbers of sub shells which all have different energy levels.
name of shells
s, d, p, f sub shell
sub shells
sub shells have different number of orbital which can hold up to 2 electrons
s
number of orbital 1
2 electrons
p
number of orbital 3
6 electrons
d
vnumber of orbital 5
10 electrons
f
number of orbital 7
14 electrons
sub shell notation
1s2 2s2 2p6
arrows in a box
each box represents one orbital each arrow represents one electron
energy level diagram
shows the energy of one of the electrons in different orbits
working out electron con fig
- electrons fill up the lowest sub shells first
- electrons fill orbital in a sub shell singly before they start sharing
- config of ions from the s and p blocks of the periodic table just remove the electrons to or from the highest energy occupied sub-shell
noble gases
you square them e.g (ar)42^2
ions
they need to be ions or they won be able to be accelerated or detected by the mass spectrum’s ion detector
transition metal configuration
chromium and coppy donate one of the 4s electrons to the 3d sub shell. it is because they prefer a more stable full or half full d sub shell
electron config for chromium
1s2 2s2 2p6 3p2 3p6 3d5 4s1
electron config for copper
1s2 2s2 2p6 3p2 3p6 3d10 4s1
electronic structure and chemical properties
the numbers of outer shell electrons decides the chemical properties of the element. you can use the periodic table to help you to work theme out
the s block elements
group 1 and 2
the s block elements qualities
have 1 or 2 outer shell electron these are easily lost to form positive ions with an inert gas config
Na 1s 2 2s 2 2p 6 3s 1 —- 1s 2 2s 2 2p 6
this is the same configuation as neon
electronic structure in the p block
group 5 6 7
electronic structure in the p block qualities
these gain 1 2 3 electrons to form negative ions
group 4 to group 7 can share electrons to form covalent bonds - covalent bonds can only occur between non metals mostly anyways
electronic structure in group 0
group 0 has completely filleds and p sub-shells and dont gain or lose electrons. their full sub shells make them inert
ionisation meaning
when electrons have been removed from an atom or molecule, it has been ionised.