Period 3 inorganic Flashcards
what is the general trend in atomic radius for period 3 ?
decrease as go along
explain the general trend in atomic radius ?
more protons in the nucleus so stronger attraction from electrons to protons. increase in nuclear charge and same shielding so electrostatic attraction between protons and outer electrons increases and therefore decreases radius
explain the trend for m.p.t and b.p.t across the period for metals
charge on the ion increases so there will be the same amount of delocalised electrons no matter the charge so as positive charge increases there will be a stronger electrostatic force and require more energy to break. and for Na-Al strength of metallic bonding increases as charge increases so more e- joins delocalised ones so will take more energy to break.
state the general trend for m.t.p and b.p.t across the period
increase up to Si then decrease
explain how structure of a metal has an effect on m.p.t across the period
they have giant structures which have higher melting points and this increases and charge on ion increases
what is the order in m.p.t from P-Ar
S8>P4>Cl>
explain how the m.p.t of non metals changes as you go across the period
they have lower than metals, the bigger the molecule (more electrons) then the stronger the van Der Waals forces so higher the m.t.p but can’t compete with the giant metallic structures (weaker)
why does Si have a higher m.p.t than the others?
it is a giant covalent structure which has a high m.t.p
define the term ionisation energy
enthalpy required to remove a mole of electrons from a mole of gaseous atoms
state the general trend for first IE across the period
increase
explain the trend in first IE across the period
number of protons increase but electrons stay in same main level, increased nuclear charge and same shielding so becomes more difficult to remove an electron as the electrostatic attraction is higher
where are the drops in IE in period 3
between Mg —> Al and P—–> S
explain the drop in IE at Aluminium
it looses a 3p electron this is a higher energy level than magnesiums (3s electron) so is easier to remove
explain the drop in IE at sulphur in period 3
the last electron in S has its last electron in spin pair with another electron therefore it is easier to remove because the repeal each other, and P’s last electron dosn’t have any so is harder to remove
