periodic properties of elements
DESCRIPTION
Periodic Classification of elementsTRANSCRIPT
TOPIC : PERIODICITY IN PROPERTIES
CHEMISTRYCLASSIFICATION OF ELEMENTSAND PERIODICITY PROPERTIES
TEACHER: Mrs. V. GOWRI (PGT-Chemistry)
BYVISHNU PRASAD VP
XI A 1
KENDRIYA VIDYALAYA
Periodic Properties
Atomic Size And RadiiIonization energyElectron Gain EnthalpyElectro negativityMetallic characterNon Metallic Character
Periodic Properties
Group Period Exception
Atomic Size / Radii Al to Ga Halogen to Noble
Gases
Ionization Energy Nitrogen-Oxygenpair
Electron Gain Enthalpy
Chlorine –Fluorine pair
Electro negativity--------
Metallic character --------
Non metallic Character
--------
An Outlook of Trends of Periodic Properties in Groups And Periods
In group, size increases from top to bottom due to formation of new shells
In period ,size decreases from left to right due to effective nuclear charge
Exceptional:In period, Halogens are slightly smaller than
noble gases. (since noble gas have completed octet)
Atomic size doesn't increase much when we move from Al to Ga due to poor shielding of inner core electrons.
Atomic Size
3 4 5 6 7 8 90
20
40
60
80
100
120
140
160
Atomic Radius vs Atomic Number
Atomic Radius vs Atomic Number
Atomic Size
Series10
50
100
150
200
250
300
350
400
Group 1 (li to Cs)Group 17 (F to I)
Atomic Size
Covalent RadiiMetallic RadiiVanderwaal’s RadiiIonic Radii
CationAnion
Atomic Radius
Anion > Atom > CationZ+ > Z > Z-
Energy required to remove an electron from an isolated gaseous atom
Na Na + + e-
Exceptional:Nitrogen – Oxygen : Though I.E., increases
along the period, nitrogen has more I.E., than Oxygen .Because nitrogen is already half filled & more stable.
Ionization Energy
Ionization Energy
The energy released when an electron is injected into an isolated gaseous atom
Cl + e- Cl- + EnergyExceptional:
F has more EGE than Cl ( in spite of decrease along the group),due toFluorine is small in sizeLone pair – Lone pair attraction is more.
Electron Gain Enthalpy
Se-ries1
-100
-50
0
50
100
150
Chart Title
Group 1Group 0
Axis Title
Electron Gain Enthalpy
The power of an atom to pull the mutually shared pair of electron towards itself. negative elements
Most electronegative element is Fluorine(4)Scales:
MillikanPauling
Example: HF : H---FH~ + --- F~ - -partial charge
Electro Negativity
Metallic CharacterIncreases along the group.Decreases along the period.
Non character Decreases along the group.Increases along the period.
Metallic And Non- metallic character
An outlook of periodic periodic properties