Non-Physical
Chemistry
, Period 3
(Na, Mg, Al, Si, P, S, Cl, Ar)
Physical Properties
Atomic Radius Proton ↑, NC ↑, successive e- added to same outermost shell, shielding
(Decrease) effect remain approx. same, ENC ↑, attraction btw nucleus + outermost e- ↑
∴ Atomic radius ↓ across period.
Ar larger atomic radius as Ar molecules not bonded to one another ∴
Radius measured is unbonded radius hence larger.
Ionic Radius Proton ↑, NC ↑, shielding effect same as no. e- in each ion same, ENC ↑,
(Decrease, then attraction btw nucleus + outermost e- increase ∴ Ionic radii decrease from
increase) Na+ to Si4+ and P3- to Cl-
Sharp increase from cation to anion as anion have one more e- shell ∴
Despite NC ↑, significant ↑ shielding effect, outermost e- further from
nucleus, attraction btw nucleus + outermost e- decreases
Cations smaller as they have one e- shell less ∴ Shielding effect weaker,
NC remains same, outermost e- closer to nucleus ∴ Attraction between
nucleus + outermost e- increases, ionic radii decreases.
Anions larger as they have extra repulsion of added e- since NC remains
the same, outermost e- now less attracted to nucleus
, First I.E. Proton ↑, NC ↑, successive e- added to same outermost shell, shielding
(Generally effect remain approx. same, ENC ↑, attraction btw nucleus + outermost e-
increases) ↑, more energy to remove outermost e- ∴ First IE increase.
w
Al lower IE as less energy to remove 3p e- as it experiences increased
shielding by filled 3s subshell
S lower IE as less energy to remove paired 3px e- due to inter-e- repulsion
Electronegativity Proton ↑, NC ↑, successive e- added to same outermost shell, shielding
(Increases) effect remain approx. same, ENC ↑, attraction btw nucleus + outermost e-
↑, electronegativity increases
Chemistry
, Period 3
(Na, Mg, Al, Si, P, S, Cl, Ar)
Physical Properties
Atomic Radius Proton ↑, NC ↑, successive e- added to same outermost shell, shielding
(Decrease) effect remain approx. same, ENC ↑, attraction btw nucleus + outermost e- ↑
∴ Atomic radius ↓ across period.
Ar larger atomic radius as Ar molecules not bonded to one another ∴
Radius measured is unbonded radius hence larger.
Ionic Radius Proton ↑, NC ↑, shielding effect same as no. e- in each ion same, ENC ↑,
(Decrease, then attraction btw nucleus + outermost e- increase ∴ Ionic radii decrease from
increase) Na+ to Si4+ and P3- to Cl-
Sharp increase from cation to anion as anion have one more e- shell ∴
Despite NC ↑, significant ↑ shielding effect, outermost e- further from
nucleus, attraction btw nucleus + outermost e- decreases
Cations smaller as they have one e- shell less ∴ Shielding effect weaker,
NC remains same, outermost e- closer to nucleus ∴ Attraction between
nucleus + outermost e- increases, ionic radii decreases.
Anions larger as they have extra repulsion of added e- since NC remains
the same, outermost e- now less attracted to nucleus
, First I.E. Proton ↑, NC ↑, successive e- added to same outermost shell, shielding
(Generally effect remain approx. same, ENC ↑, attraction btw nucleus + outermost e-
increases) ↑, more energy to remove outermost e- ∴ First IE increase.
w
Al lower IE as less energy to remove 3p e- as it experiences increased
shielding by filled 3s subshell
S lower IE as less energy to remove paired 3px e- due to inter-e- repulsion
Electronegativity Proton ↑, NC ↑, successive e- added to same outermost shell, shielding
(Increases) effect remain approx. same, ENC ↑, attraction btw nucleus + outermost e-
↑, electronegativity increases
