elements in period 3 smkbbst
DESCRIPTION
Period 3 elementsTRANSCRIPT
ELEMENTS IN A PERIOD
PERIODIC TABLE OF ELEMENTS (PG 72)
Period 3 elements – Na, Mg, Al, Si, P, S, Cl and Ar
ELEMENTS IN PERIOD 3 AND THE ELECTRON ARRANGEMENTS IN ALL
ELEMENTS IN PERIOD 3.
Element of period 3
Na Mg Al Si P S Cl Ar
Electron arrangement
2.8.1 2.8.2 2.8.3 2.8.4
2.8.5
2.8.6
2.8.7
2.8.8
+ e-e-
e-
e-e-
e- e-
e-e-
e-e-
2.8.1
+ e-e-
e-
e-e-
e-e-e-e-
e-e-
2.8.8
e-e-
e-e-
e-e-
e-+ e-e-
e-
e-e-
e- e-
e-e-
e-e-
2.8.4
e-
e-
e-
PROPERTIES OF ELEMENTS IN PERIOD 3
Element of period 3
Na Mg Al Si P S Cl Ar
Proton number
11 12 13 14 15 16 17 18
Electron arrangement
2.8.1 2.8.2 2.8.3 2.8.4
2.8.5
2.8.6
2.8.7
2.8.8
Electronic structure
Atomic radius (pm)
186 160 143 118 110 104 100 94
Physical state at room temperature
Solid Solid Solid Solid
Solid
Solid
Gas Gas
Electronegativity
0.9 1.2 1.5 1.8 2.1 2.5 3.0 -
THE CHANGES IN THE PROPERTIES OF ELEMENTS
ACROSS PERIOD 3
• THE PHYSICAL STATE OF ELEMENTS IN PERIOD 3 ARE SOLIDS EXCEPT CHLORINE AND ARGON WHICH ARE GASES.
• ATOMIC RADIUS OF ELEMENTS DECREASES DUE TO INCREASING NUCLEI ATTRACTION ON THE VALENCE ELECTRONS.
• ELECTRONEGATIVITY OF ELEMENTS INCREASES DUE TO INCREASING NUCLEI ATTRACTION ON THE VALENCE ELECTRONS AND THE DECREASE IN ATOMIC SIZE.
THE CHANGE OF PROPERTIES OF THE OXIDES OF ELEMENTS
ACROSS PERIOD 3
• SODIUM AND MAGNESIUM FORM BASIC METAL OXIDES.
• ALUMINIUM FORM AMPHOTERIC OXIDE. [AN AMPHOTERIC OXIDE CAN REACT WITH BOTH ACIDS AND BASES TO FORM SALTS AND WATER].
• SILICON, PHOSPHORUS, SULPHUR AND CHLORINE FORM ACIDIC NON-METAL OXIDES.
THE ACID-BASE PROPERTIES OF THE OXIDE
OF PERIOD 3 ELEMENTS
OxideObservation
InferenceWith water
pH Value
With NaOH With HNO3
Na2O Soluble. Forms
colourless solution
13 - 14 Insoluble Soluble. Forms colourless solution
Strong base.Strong alkali.
MgO Slightly soluble.
Colourless solution
8 - 9 Insoluble Soluble. Forms colourless solution
A basic oxide.Weak alkali.
Al2O3Insoluble 7 Soluble.
Forms colourless solution
Soluble. Forms colourless solution
An amphoteric oxide, with acidic
and bacic properties.
SiO2Insoluble 7 Soluble.
Forms colourless solution
Insoluble An acidic oxide.
THE ACID-BASE PROPERTIES OF THE OXIDE OF PERIOD 3 ELEMENTS
OxideObservation
InferenceWith water pH Value With NaOH
With NH3
P4O10Soluble. Forms
colourless solution
2 - 3 Soluble. Forms
colourless solution
Insoluble An acidic oxide.
SO2Soluble. Forms
colourless solution
2 - 3 Soluble. Forms
colourless solution
Insoluble Form an acid.An acidic oxide.
Cl2O7Soluble. Forms
colourless solution
1 Soluble. Forms
colourless solution
Insoluble Strong acid formed.
An acidic oxide.
CONCLUSION
The oxide of elements in period 3 change from basic to amphoteric and then to an acidic nature as we go across the period towards the right.
PREDICT THE CHANGES IN THE PROPERTIES OF ELEMENTS ACROSS OTHER PERIODS
• THE ELEMENTS CHANGES FROM:• STATE - SOLID TO GAS
• METAL TO NON-METAL
• CONDUCTOR TO
NON-CONDUCTOR
• THE FOLLOWING PROPERTIES DECREASES FROM LEFT TO RIGHT:• ATOMIC SIZE
• MELTING POINTS
• BOILING POINT
• THE FOLLOWING PROPERTIES INCREASE FROM LEFT TO RIGHT:• PROTON NUMBER
• THE NUMBER OF VALENCE ELECTRON
• ELECTRONEGATIVITY
SEMI METALS @ METALLOID• SEMI-METALS OR METALLOIDS ARE WEAK
CONDUCTORS OF ELECTRICITY.
• SEMI-METALS SUCH AS SILICON AND GERMANIUM ARE USED AS SEMICONDUCTORS.
• SEMICONDUCTORS ARE USED TO MAKE DIODES AND TRANSISTORS.
• DIODES AND TRANSISTORS ARE USED TO MAKING OF MICROCHIPS.
• SEMICONDUCTORS ENABLES US TO SURF INTERNET AND WATCH TELEVISION.
USES OF SEMI METALS IN INDUSTRY
Uses of semi metals