Periodic Properties of Elements (Class X CBSE & ICSE)

INTRODUCTION
 THE PERIODIC TABLE IS A TABULAR
ARRANGEMENT OF THE CHEMICAL ELEMENTS,
ORDERED BY THEIR ATOMIC NUMBER,
ELECTRONIC CONFIGURATIONS AND
RECURRING CHEMICAL PROPERTIES.
 THIS ORDERING SHOWS PERIODIC TRENDS,
SUCH AS ELEMENTS WITH SIMILAR BEHAVIOUR
IN THE SAME COLUMN. IT ALSO SHOWS FOUR
RECTANGULAR BLOCKS WITH SOME
APPROXIMATELY SIMILAR CHEMICAL
PROPERTIES. IN GENERAL, WITHIN ONE ROW
(PERIOD) THE ELEMENTS ARE METALS ON THE
LEFT, AND NON-METALS ON THE RIGHT.
5/1/2020EXCELLENCE CLASSES

WHY DO WE NEED TO CLASSIFY
ELEMENTS
 IN 1800, ONLY 31 ELEMENTS WERE KNOWN. BY 1865,
THE NUMBER OF IDENTIFIED ELEMENTS HAD MORE
THAN DOUBLED TO 63.
 THERE ARE TOTAL OF 118 ELEMENTS KNOWN SO
FAR AND THE DISCOVERY OF NEW ELEMENTS STILL
CONTINUES. EVERY ELEMENT HAS ITS OWN
IMPORTANCE, SOME OF THEM ARE USEFUL WHILE
OTHERS MAY BE HARMFUL. THE HARMFUL
ELEMENTS MAY ALSO BE USEFUL IN OTHER WAY,
LIKE RADIOACTIVE ELEMENTS.
 IT IS NECESSARY TO STUDY THE CHEMICAL AND
PHYSICAL PROPERTIES OF EACH OF THE ELEMENTS
PRESENT AROUND US BECAUSE EVERY ELEMENT IS
RELATED TO OUR LIFE IN SOME OR OTHER WAY.
WITH SUCH A LARGE NUMBER OF ELEMENTS IT IS
VERY DIFFICULT TO STUDY INDIVIDUALLY THE

CHEMISTRY OF ALL THESE ELEMENTS AND THEIR
INNUMERABLE COMPOUNDS INDIVIDUALLY. TO EASE OUT
THIS PROBLEM, SCIENTISTS SEARCHED FOR A
SYSTEMATIC WAY TO ORGANISE THEIR KNOWLEDGE BY
CLASSIFYING THE ELEMENTS. NOT ONLY THAT IT WOULD
RATIONALIZE KNOWN CHEMICAL FACTS ABOUT ELEMENTS,
BUT EVEN PREDICT NEW ONES FOR UNDERTAKING
FURTHER STUDY.
 PERIODIC TABLE IS THE TOOL WHICH IS USED TO
CLASSIFY THE KNOWN ELEMENTS IN GROUPS.
 IT HELPS US TO UNDERTAKE A SYSTEMATIC STUDY OF THE
VARIOUS ELEMENTS FOUND IN NATURE WITHOUT WHICH IT
WOULD HAVE BEEN IMPOSSIBLE FOR US TO STUDY ALL
THE ELEMENTS IN THE TABLE. WITH THE HELP OF
PERIODIC TABLE A COMPARATIVE STUDY OF THE
ELEMENTS AND THEIR COMPOUNDS CAN BE DONE.
 PERIODIC TABLE ALSO HELPS US TO ANALYSE THE
PERIODIC TREND IN VARIOUS PROPERTIES SUCH AS

 DOBEREINER WAS THE FIRST SCIENTIST
TO CLASSIFY THE ELEMENTS IN SOME
GROUPS.
 HE TRIED TO CLASSIFY THE ELEMENTS
WITH SIMILAR PROPERTIES IN GROUPS
OF THREE ELEMENTS (TRIADS). HE
COULD SUCCEED IN MAKING ONLY A FEW
TRIADS.
 IN THE TRIADS OF ELEMENTS THE
ATOMIC WEIGHT OF THE MIDDLE
ELEMENT WAS THE SSARITHMETIC MEAN
OF THE ATOMIC WEIGHTS OF THE OTHER

REJECTION OF DOBEREINER’S TRIADS
1. MANY DISSIMILAR ELEMENTS WERE GROUPED IN THE TRIAD.
2. QUITE LARGE NUMBER OF ELEMENTS COULD NOT BE
GROUPED INTO TRIADS.

NEWLANDS LAW OF OCTAVES -
1866
 IN 1866, AN ENGLISH CHEMIST, JOHN
NEWLANDS NOTED THAT EVERY EIGHTH
ELEMENT SHOWED SIMILAR PHYSICAL AND
CHEMICAL PROPERTIES, WHEN THE
ELEMENTS ARE PLACED IN THE INCREASING
ORDER OF THEIR ATOMIC MASSES. THIS
WAS CALLED AS THE NEWLANDS’ LAW OF
OCTAVES.
 THE LAW STATES THAT WHEN ELEMENTS
ARE PLACED IN THE INCREASING ORDER OF
ATOMIC MASSES, THE PROPERTIES OF THE
EIGHTH ELEMENT ARE REPEATED.
 NEWLANDS ARRANGED THE ELEMENTS THE
FOLLOWING MANNER : 5/1/2020EXCELLENCE CLASSES

REJECTION FOR NEWLANDS’ LAW OF
OCTAVES
1. IT DID NOT EXTEND BEYOND CALCIUM AND
COULD NOT INCLUDE ALL ELEMENTS.
2. IT DID NOT RECOGNIZE TRANSITIONAL
ELEMENTS.

MENDELEEV’S PERIODIC
TABLE
• WHILE DOBEREINER INITIATED THE STUDY OF PERIODIC
RELATIONSHIP, IT WAS MENDELEEV WHO WAS
RESPONSIBLE FOR PUBLISHING THE PERIODIC LAW
FOR THE FIRST TIME. IT STATES AS FOLLOWS :
• MENDELEEF’S PERIODIC LAW : THE PHYSICAL AND
CHEMICAL PROPERTIES OF ELEMENTS ARE A PERIODIC
FUNCTION OF THEIR ATOMIC WEIGHTS.
• IF THE ELEMENTS ARE ARRANGED IN ORDER OF THEIR
INCREASING ATOMIC WEIGHTS, AFTER A REGULAR
INTERVAL ELEMENTS WITH SIMILAR PROPERTIES ARE
REPEATED.
• ON THE BASIS OF HIS LAW, MENDELEEV PROPOSED A
PERIODIC TABLE FOR CLASSICICATION OF ELEMENTS
WHICH IS KNOWN AS MENDELEEF’S PERIODIC TABLE5/1/2020EXCELLENCE CLASSES

MENDELEEV’S PERIODIC
TABLE
• MENDELÉEV'S RESEARCH WAS BASED ON THE 63
ELEMENTS THAT WERE KNOWN AT THAT TIME.
• HE STUDIED THE RELATIONSHIP BETWEEN THE ATOMIC
MASSES OF THE ELEMENTS AND THEIR PHYSICAL AND
CHEMICAL PROPERTIES.
• HE STUDIED THE FORMATION OF HYDRIDES AND OXIDES
OF THE ELEMENTS AND TREATED THIS AS ONE OF THE
BASIC PROPERTIES OF AN ELEMENT.
• THE PERIODIC TABLE CONTAINS VERTICAL COLUMNS
CALLED ‘GROUPS’ AND HORIZONTAL ROWS CALLED
‘PERIODS HE PLACED ELEMENTS THAT HAD SIMILAR
PROPERTIES UNDER
VERTICAL COLUMNS, LEAVING BLANK SPACES FOR
ELEMENTS NOT YET DISCOVERED.

MERITS OR ADVANTAGES OF
MENDELEEV’S PERIODIC TABLE:
 STUDY OF ELEMENTS: FIRST TIME ALL KNOWN
ELEMENTS WERE CLASSIFIED IN A GROUP ACCORDING
TO
 THEIR SIMILAR PROPERTIES. SO, STUDY OF THE
PROPERTIES OF ELEMENTS BECOME EASIER.
 PREDICTING NEW ELEMENTS: IT GAVE
ENCOURAGEMENT TO THE DISCOVERY OF NEW
ELEMENTS AS
 SOME GAPS WERE LEFT IN IT. SC, GE, TC WERE THE
ELEMENTS FOR WHOM POSITION AND PROPERTIES WERE
DEFINED BY MENDELEEV EVEN BEFORE THEIR
DISCOVERIES AND HE LEFT THE BLANK SPACES FOR
THEM IN THE TABLE.
 BLANK SPACE AT ATOMIC WEIGHT 72 IN SI GROUP WAS
CALLED EKA SILICON AND ELEMENT DISCOVERED LATER
WAS NAMED GERMANIUM.
• EKA ALUMINIUM: GALLIUM
• EKA BORON: SCANDIUM
• EKA MANGANESE: TECHNETIUM 5/1/2020EXCELLENCE CLASSES

DEMERITS OF MENDELEEV’S
PERIODIC TABLE:
• POSITION OF HYDROGEN: HYDROGEN RESEMBLES
BOTH, THE ALKALI METALS (1A) AND HALOGENS(VII A)
IN PROPERTIES SO MENDELEEV COULD NOT DECIDE
WHERE TO PLACE IT.
• POSITION OF ISOTOPES: AS ATOMIC WEIGHT OF
ISOTOPES DIFFER, THEY SHOULD HAVE BEEN PLACED
IN DIFFERENT POSITION IN MENDELEEV’S PERIODIC
TABLE. BUT THERE WERE NO SUCH POSITIONS FOR
ISOTOPES IN MENDELEEV’S PERIODIC TABLE
• ANOMALOUS PAIRS OF ELEMENTS: THERE WERE SOME
PAIR OF ELEMENTS WHICH DID NOT FOLLOW
THEINCREASING ORDER OF ATOMIC WEIGHTS. E.G: AR
AND CO WERE PLACED BEFORE K AND NI
RESPECTIVELY IN THE TABLE BUT HAVING HIGHER

 POSITION OF RARE EARTH METALS
ALL THE 14 RARE EARTH METALS WERE
PLACED TOGETHER AT ONE PLACE INSPITE
OF DIFFERENT ATOMIC WEIGHTS

MODERN PERIODIC TABLE
 PERIODIC TABLE: IT IS THE TABLE OF
CHEMICAL ELEMENTS ARRANGED IN ORDER
OF ATOMIC NUMBER SUCH THAT ELEMENTS
WITH SIMILAR ATOMIC STRUCTURE APPEAR IN
THE VERTICAL COLUMNS.
• MODERN PERIODIC LAW: THE MODERN
PERIODIC LAW STATES
 “THE CHEMICAL AND PHYSICAL PROPERTIES
OF ELEMENTS ARE A PERIODIC FUNCTION OF
THEIR ATOMIC NUMBERS”.
 MODERN PERIODIC TABLE IS BASED ON THE
MODERN PERIODIC LAW.

MODERN PERIODIC TABLE 5/1/2020EXCELLENCE CLASSES

CLASSIFICATION OF
ELEMENTS
• GROUP 1 ON EXTREME LEFT POSITION
CONTAINS ALKALI METALS (LI, NA, K, RB, CS
AND FR).
• THE ALKALINE EARTH METALS ARE METALLIC
ELEMENTS FOUND IN THE GROUP 2 OF THE
PERIODIC TABLE.
• ELEMENTS PRESENT IN GROUPS 3 TO 12 IN THE
MIDDLE OF THE PERIODIC TABLE ARE CALLED
TRANSITION ELEMENTS.
• THESE ELEMENTS HAVE THEIR PENULTIMATE
SHELL (SECOND LAST)INCOMPLETELY FILLED

• GROUP 18 ON EXTREME RIGHT SIDE POSITION CONTAIN
NOBLE GASES ( HE, NE, AR, KR, XE AND RN ).
THEIR OUTERMOST SHELLS CONTAIN 8 ELECTRONS EXCEPT
HE AS ITS OUTERMOST SHELL IS K SHELL AND IT CAN HOLD
ONLY A MAXIMUM OF 2 ELECTRONS.
• INNER TRANSITION ELEMENTS:
• 14 ELEMENTS WITH ATOMIC NUMBERS 58 TO 71 (CE TO LU)
ARE CALLED LANTHANIDES AND THEY ARE PLACED ALONG
WITH
THE ELEMENT LANTHANUM (LA), ATOMIC NUMBER 57 IN THE
SAME POSITION (GROUP 3 IN PERIOD 6) BECAUSE OF VERY
CLOSE
RESEMBLANCE BETWEEN THEM. HOWEVER, FOR
CONVENIENCE SAKE, THEY ARE SHOWN SEPARATELY BELOW
THE MAIN PERIODIC
TABLE.
• 14 ELEMENTS WITH ATOMIC NUMBERS 90 TO 103 (TH TO LR)
ARE CALLED ACTINIDES AND THEY ARE PLACED ALONG
WITH THE
ELEMENT ACTINIUM (AC), ATOMIC NUMBER 89 IN THE SAME
POSITION (GROUP 3 IN PERIOD 7) BECAUSE OF VERY CLOSE
RESEMBLANCE BETWEEN THEM. THEY ARE ALSO SHOWN
SEPARATELY BELOW THE MAIN PERIODIC TABLE ALONG WITH

• THE LONG FORM OFPERIODIC TABLE CAN
BE CLASSIFIED INTO 4 BLOCKS ON THE
BASIS OF THEIR OUTER ELECTRONIC
CONFIGURATION:
1. S- BLOCK ELEMENTS : GROUP 1 AND 2
2. P- BLOCK ELEMENTS : GROUP 13 TO
GROUP 18
3. D – BLOCK ELEMENTS : GROUP 3 TO 12
(TRANSITION ELEMENTS)
4. F – BLOCK ELEMENTS : INNERTRANSITION
ELEMENTS (LANTHANIDE AND ACTINIDES)

Something about the Periodic
table
 GROUPS ( THE VERTICAL COLUMNS IN THE
PERIODIC TABLE)
 THERE ARE 18 GROUPS.
 ELEMENTS HAVE SIMILAR PROPERTIES IN A
GROUP
 NO. OF SHELLS INCREASE AS WE MOVE
DOW THE GROUP
 SIZE OF THE ELEMENT INCREASES AS
SHELLS INCREASES
 THE ELEMENTS HAVE SAME NO.OF VALANCE
ELECTRONS IN THE OUTERMOST SHELLS

 PERIODS(HORIZONTAL ROWS)
 THERE ARE 7 PERIODS IN THE PERIODIC TABLE
 ACROSS A PERIOD,THE NUMBER OF ELECTRONS
INCREASE BY ONE WITH EACH ELEMENT.
 NUMBER OF SHELLS REMAINS THE SAME.
 ELEMENTS SWITCH FROM METALLIC TO NON-
METALLIC CHARACTER.

PERIODICITY
 PERIODICITY OF ELEMENTS MEANS THE
RECURRENCE OF SIMILAR PROPERTIES OF THE
ELEMENTS AFTER CERTAIN REGULAR
INTERVALS WHEN THEY ARE ARRANGED IN THE
ORDER OF INCREASING ATOMIC NUMBERS.
 CAUSE OF PERIODICITY OF ELEMENTS
THE CAUSE OF PERIODICITY OF THE PROPERTIES
OF ELEMENTS IS THE REPETITION OF SIMILAR
ELECTRONIC CONFIGURATION OF THEIR ATOMS
IN THE OUTERMOST ENERGY SHELL (OR
VALENCE SHELL) AFTER CERTAIN REGULAR
INTERVALS.

PERIODIC PROPRTIES
 THE PROPERTIES OF ELEMENTS WHICH
CHANGE PERIODICALLY WITH ATOMIC
NUMBERS ARECALLED PERIODIC
PROPERTIESAND THIS PHENOMENON IS
CALLED PERIODICITY OF THE ELEMENTS.
 THE VARIOUS PERIODIC PROPERTIES ARE:
 ATOMIC RADIUS
 IONISATION ENERGY /POTENTIAL
 ELECTRON AFFINITY / ELECTRON GAIN
ENTHALPY
 ELECTRONEGATIVITY
 METALLIC CHARACTER
 NON- METALLIC CHARACTER. 5/1/2020EXCELLENCE CLASSES

ATOMIC RADIUS
 IT IS THE MOST PROBABLE DISTANCE
BETWEEN THE CENTRE OF THE NUCLEUS
OF AN ATOM AND ITS OUTERMOST SHELL OF
ELECTRONS.
 UNIT – ANGSTRONG (1 A = 10^ -10)
 FACTORS INFLUENCING ATOMIC RADIUS
• NUMBER OF SHELLS – AS NO.OF SHELLS
ATOMIC RADIUS
 NUCLEAR CHARGE – AS NUCLEAR CHARGE
ATOMIC RADIUS

• ATOMIC RADII (ACROSS A ROW) AS NUCLEAR
CHARGE.
• IN EACH GROUP (VERTICAL COLUMN), THE ATOMIC
RADIUS TENDS TO INCREASE WITH THE PERIOD
NUMBER.

IONISATION ENERGY
 IONIZATION ENERGY REQUIRED TO REMOVE AN
ELECTRON FROM A NEUTRAL ATOM IN ITS GASEOUS
PHASE.
 CONCEPTUALLY, IONIZATION ENERGY IS THE
OPPOSITE OF ELECTRONEGATIVITY.
 THE LOWER THIS ENERGY IS, THE MORE READILY THE
ATOM BECOMES A CATION. THEREFORE, THE HIGHER
THIS ENERGY IS, THE MORE UNLIKELY IT IS THE ATOM
BECOMES A CATION.
 GENERALLY, ELEMENTS ON THE RIGHT SIDE OF THE
PERIODIC TABLE HAVE A HIGHER IONIZATION ENERGY5/1/2020EXCELLENCE CLASSES

 ELEMENTS ON THE LEFT SIDE OF THE PERIODIC
TABLE HAVE LOW IONIZATION ENERGIES
BECAUSEOF THEIR WILLINGNESS TO LOSE
ELECTRONS AND BECOME CATIONS.
HENCE,IONIZATION ENERGY INCREASES FROM
LEFT TO RIGHT ON THE PERIODIC TABLE.
 THE NOBLE GASES POSSESS VERY HIGH
IONIZATION ENERGIES BECAUSE OF THEIR FULL
VALENCE SHELLS .
 HELIUM HAS THE HIGHEST IONIZATION ENERGY
OF ALL THE ELEMENTS.

•THE IONIZATION ENERGY OF THE ELEMENTS WITHIN A PERIOD
GENERALLY INCREASES FROM LEFT TO RIGHT. THIS IS DUE TO VALENCE
SHELL STABILITY.
• THE IONIZATION ENERGY OF THE ELEMENTS WITHIN A GROUP
GENERALLY DECREASES FROM TOP TO BOTTOM. THIS IS DUE TO
ELECTRON SHIELDING.

ELECTRON AFFINITY
 ELECTRON AFFINITY IS THE AMOUNT OF
ENERGY RELEASED WHEN AN ISOLATED
NEUTRAL GASEOUS ATOM TAKES UP AN
EXTRA ELECTRON TO FORM UNINEGATIVE
GASEOUS ION.
 UNITS – ev/atom or KJ/mol or Kcal/mol.
 NOBLE GASES HAVE 0 ELECTRON AFFINITY
AS THEY HAVE NO TENDENCY TO TAKE
UPEXTRA ELECTRON.

FACTORS AFFECTING
ELECTRON AFFINITY
 ATOMIC SIZE – SMALLER THE ATOMIC SIZE ,
MORE WILL BE THE ELECTRON AFFINITY AS
THE ATTRACTIVE FORCES BETWEEN THE
NUCLEUS AND THE ADDITIONAL ELECTRON
IS MORE.
 NUCLEAR CHARGE – THE MORE THE
NUCLEAR CHARGE THE MORE WILL BE THE
ELECTRON AFFINITY , AS NUCLEAR CHARGE
INCREASES THE FORCE OF ATTRACTION
BETWEEN NUCLEUS AND ADDITIONAL
ELECTRONS INCREASES.

ALONG A PERIOD (LEFT TO RIGHT) – EFFECTIVE NUCLEAR CHARGE SIZE OF
ATOM ELECTRON AFFINITY
DOWN A GROUP ( TOP TO BOTTOM) - EFFECTIVE NUCLEAR CHARGE SIZE OF
ATOM ELECTRON AFFINITY

ELECTRONEGATIVITY
 THE TENDENCY OF AN ATOM TO ATTRACT
SHARED PAIROF ELECTRONS TO ITSELF
WHEN COMBINED IN A COMPOUND IS
CALLED ELECTRONEGATIIVITY.
 IF THE ELECTRONEFGATIVITY IS LESS THAN
1.7 THEN BOND WILL BE COVALENT.
 E.G N2 ; N=3 ; DIFFERENCE = 0
 IF THE ELECTRONEGATIVITY IS MORE THAN
1.7 THEN THE BOND WILL BE IONIC.
 E.G MgF2 ; Mg = 1.2, F= 4 ; DIFFERENCE = 4-
1.2 = 2.8 5/1/2020EXCELLENCE CLASSES

FACTORS AFFECTING
ELECTRONEGATIVITY
 ATOMIC SIZE – LARGR THE SIZE OF ATOM
LESSER IS THE ELECTRONEGATIVITY.
 NUCLEAR CHARGE - THE MORE THE
NUCLEAR CHARGE MORE THE
ELECTRONEGATIVITY AS WITH THE
INCREASE IN THE NUCLEAR CHARGE
ELECTRONS ARE ATTRACTED BY A GREATER
FORCE.

ALONG A PERIOD (LEFT TO RIGHT) – EFFECTIVE NUCLEAR CHARGE SIZE OF
ATOM SO TENDENCY TO WITHDRAW SHARED PAIR OF ELECTRONS
ELECTRONEGATIVITY
DOWN A GROUP ( TOP TO BOTTOM) - EFFECTIVE NUCLEAR CHARGE SIZE OF ATOM
SO TENDENCY TO WITHDRAW SHARED PAIR OF ELECTRONS ELECTRON
ELECTRONEGATIVITY

METALLIC AND NON METALLIC
CHARACTER
 METALLIC CHARACTER RELATES TO THE ABILITY TO
LOSE ELECTRONS.
 NONMETALLIC CHARACTER RELATES TO THE ABILITY
TO GAIN ELECTRONS.
 METALLIC CHARACTERISTICS DECREASE FROM
LEFT TO RIGHT ACROSS A PERIOD. THIS IS CAUSED
BY THE DECREASE IN RADIUS OF THE ATOM THAT
ALLOWS THE OUTER ELECTRONS TO IONIZE MORE
READILY.
 METALLIC CHARACTERISTICS INCREASE DOWN A
GROUP. DECREASE IN NUCLEAR CHARGE CAUSES
THE ATOMIC RADIUS TO INCREASE THUS THE OUTER
ELECTRONS IONIZES MORE READILY THAN
ELECTRONS IN SMALLER ATOMS. 5/1/2020EXCELLENCE CLASSES

TO SUM IT UP

Periodic Properties of Elements (Class X CBSE & ICSE)

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Ähnlich wie Periodic Properties of Elements (Class X CBSE & ICSE)

Ähnlich wie Periodic Properties of Elements (Class X CBSE & ICSE) (20)

Mehr von KeyurMaradiya

Mehr von KeyurMaradiya (7)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

Periodic Properties of Elements (Class X CBSE & ICSE)

Hinweis der Redaktion