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Elements in Period 3

 
4.6 Eelements in Period 3
 
The image shows a diagram with the title ‘ELEMENTS IN PERIOD 3’ in the center. Surrounding the title are boxes connected by arrows, each containing the name and symbol of a different element from Period 3 of the periodic table. The elements listed are: - Sodium, Na - Magnesium, Mg - Aluminium, Al - Silicon, Si - Phosphorus, P - Sulphur, S - Chlorine, Cl - Argon, Ar The logo ‘Pandai’ is displayed in the top right corner.
 
Elements in Period 3
  • The elements in Period 3 will show a gradual change in physical and chemical properties, as going across the period. 
  • The elements in Period 3 are as belows:

This image shows a periodic table of elements. The table is color-coded with different sections highlighted in various colors. The elements in the first column (Group 1) are in red, the second column (Group 2) is in light yellow, and the last column (Group 18) is in green. The elements in the third to twelfth columns (transition metals) are in white. The elements in the thirteenth to seventeenth columns are in purple. The background of the table is light blue.
 
Uses of Period 3 Elements
  • Magnesium, Mg as a substance in a lighter.
  • Aluminium, Al as a substance in cans.
  • Phosphorus, P as a substance in fireworks.
  • Sulphur, S as fungicides.
 
Changes in Physical Properties of Elements Across Period 3

 

Group 1 2 13 14 15 16 17 18
Element Na Mg Al Si P S Cl Ar
  \(\xrightarrow[]{\text{Across period}}\)

 
Atomic Radius Decreases
  • There are only three shells, but the number of electron increases.
  • The increase in the number of electrons means there is an increase in the number of protons, which result in the higher electrostatic force.
  • The increase of electrostatic force pulls the valence electron closer to the nucleus.
The Number of Valence Electrons Increases
  • The number of electrons of the element increases.  
The Electronegativity Increases
  • The atomic radius decreases as the number of protons increases.
  • As the number of protons increases, the electrostatic force also increases and creates a tendency to attract electrons.
  • The left side of the period is less electronegative than the right side of the period.
The Melting Point and Boiling Point
  • Increases from the left to the middle of the period, and then decrease again.
Nature of Metals
  • The elements change from metal to metalloid, and then non-metal as the electronegativity increases.
Nature of Oxides
  • The oxides of the elements change from basic to amphoteric and then to acidic across the period.
 
Uses of Semi-Metallic Elements
  • Metalloids like silicon are used as semiconductors in the manufacture of electronic microchips.
  • The uses of electronic microchips in the production of computers and mobile phones.
 

 

 

 

The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of pandai.

Elements in Period 3

 
4.6 Eelements in Period 3
 
The image shows a diagram with the title ‘ELEMENTS IN PERIOD 3’ in the center. Surrounding the title are boxes connected by arrows, each containing the name and symbol of a different element from Period 3 of the periodic table. The elements listed are: - Sodium, Na - Magnesium, Mg - Aluminium, Al - Silicon, Si - Phosphorus, P - Sulphur, S - Chlorine, Cl - Argon, Ar The logo ‘Pandai’ is displayed in the top right corner.
 
Elements in Period 3
  • The elements in Period 3 will show a gradual change in physical and chemical properties, as going across the period. 
  • The elements in Period 3 are as belows:

This image shows a periodic table of elements. The table is color-coded with different sections highlighted in various colors. The elements in the first column (Group 1) are in red, the second column (Group 2) is in light yellow, and the last column (Group 18) is in green. The elements in the third to twelfth columns (transition metals) are in white. The elements in the thirteenth to seventeenth columns are in purple. The background of the table is light blue.
 
Uses of Period 3 Elements
  • Magnesium, Mg as a substance in a lighter.
  • Aluminium, Al as a substance in cans.
  • Phosphorus, P as a substance in fireworks.
  • Sulphur, S as fungicides.
 
Changes in Physical Properties of Elements Across Period 3

 

Group 1 2 13 14 15 16 17 18
Element Na Mg Al Si P S Cl Ar
  \(\xrightarrow[]{\text{Across period}}\)

 
Atomic Radius Decreases
  • There are only three shells, but the number of electron increases.
  • The increase in the number of electrons means there is an increase in the number of protons, which result in the higher electrostatic force.
  • The increase of electrostatic force pulls the valence electron closer to the nucleus.
The Number of Valence Electrons Increases
  • The number of electrons of the element increases.  
The Electronegativity Increases
  • The atomic radius decreases as the number of protons increases.
  • As the number of protons increases, the electrostatic force also increases and creates a tendency to attract electrons.
  • The left side of the period is less electronegative than the right side of the period.
The Melting Point and Boiling Point
  • Increases from the left to the middle of the period, and then decrease again.
Nature of Metals
  • The elements change from metal to metalloid, and then non-metal as the electronegativity increases.
Nature of Oxides
  • The oxides of the elements change from basic to amphoteric and then to acidic across the period.
 
Uses of Semi-Metallic Elements
  • Metalloids like silicon are used as semiconductors in the manufacture of electronic microchips.
  • The uses of electronic microchips in the production of computers and mobile phones.
 

 

 

 

The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of pandai.
Chapter : Periodic Table of Elements
Topic : Elements in Period 3
Form 4 Chemistry
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