4.3 (a) group 1
TRANSCRIPT
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Defination
An alkali metal is any element other than hydrogen found in the first column of the periodic table. These elements include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs) and francium (Fr):
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The Group 17 elements ( F, Cl, Br, I, At)The Group 17 elements ( F, Cl, Br, I, At)
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MELTINGPOINT
MELTINGPOINT
DENSITYDENSITYBOILING
POINT
BOILING
POINT GENERAL
PHYSICAL
PROPERTIES
GROUP 1 (( Lithium, Sodium, Potassium, Rubidium, Cesium, Lithium, Sodium, Potassium, Rubidium, Cesium,
Francium )Francium )
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Physical Properties*things that we can see
Atomic numberAtomic radii
Electronegativity
DensityMelting pointBoiling point
PhaseColor
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Halogen Atomic number
Electron Configuration
Atomic radii (nm)
Electronegativity
FlourineChlorineBromineIodine
9173553
2.72.8.72.8.18.72.8.18.18.7
0.0710.0990.1440.133
4.03.02.82.5
Atomic NumberAtomic Number The atomic number can be fined from periodic tableThe atomic number can be fined from periodic table Example: Example:
Down the group, atomic number will increaseDown the group, atomic number will increase
Atomic number 17
Cl
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Atomic radii or Atomic SizeAtomic radii or Atomic Size Based on atomic number.Based on atomic number. Example : -F atomic number is 9 so that the Example : -F atomic number is 9 so that the
electron configuration is 2:7 . electron configuration is 2:7 . This shows that F has 2 shells.This shows that F has 2 shells.
-I atomic number is 53, the electron -I atomic number is 53, the electron
configuration is 2:8:18:18:7. This show that configuration is 2:8:18:18:7. This show that
has 5 shells.has 5 shells.
-the size of I atom is bigger than F-the size of I atom is bigger than F Down the group the atomic radii or size is increaseDown the group the atomic radii or size is increase
IF
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ElectronegativityElectronegativity
Is the power of outer electron attraction to the Is the power of outer electron attraction to the nucleusnucleus
Decrease going down a groupDecrease going down a group
The large atomic number caused the large sizeThe large atomic number caused the large size
So that the outer most shell is far from the nucleusSo that the outer most shell is far from the nucleus
Then the electronegativity is lowerThen the electronegativity is lower
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Density Density Has lower densityHas lower densityBut density is increase when going down But density is increase when going down
the groupthe group
Melting and Boiling Point.Melting and Boiling Point.Has lower melting and boiling pointHas lower melting and boiling pointBecause of the lower Van der Waals Because of the lower Van der Waals
force between the molecule.force between the molecule.But the melting and boiling point But the melting and boiling point
increase when going down the group.increase when going down the group.Parallel to the density of each elementsParallel to the density of each elements..
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PhasePhaseThe phase changes from gaseous The phase changes from gaseous
to liquid to solid when going down to liquid to solid when going down the groupthe group
Because the melting and boiling Because the melting and boiling point is increase.point is increase.
Halogen Phase
FlourineChlorineBromineIodine
GasGasLiquidSolid
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ColourColour
Every elements has different coloursEvery elements has different colours
Pale yellow gas Greenish yellow gas
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Reddish-brown liquid
Purplish-black solid
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alkaline
metal
water
CHEMICAL PROPERTIES OF HALOGEN GROUPS
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Boiling pointBoiling point
decrease from Lithium to decrease from Lithium to PotassiumPotassium
the metal bonding will weak the metal bonding will weak because of the increasing of because of the increasing of atomic sizeatomic size
Changes in Physical Properties Changes in Physical Properties from Lithium to Potassiumfrom Lithium to Potassium
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Changes in Physical Properties Changes in Physical Properties from Lithium to Kaliumfrom Lithium to Kalium
Melting pointMelting point
decrease from Lithium to decrease from Lithium to PotassiumPotassiumthe metal bonding will weak the metal bonding will weak because of the increasing of because of the increasing of atomic sizeatomic size
Changes in Physical Properties Changes in Physical Properties from Lithium to Potassiumfrom Lithium to Potassium
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Density
increase from Lithium to Potassium
the increasing of atomic mass is higher than the increasing of atomic radius
Changes in Physical Properties Changes in Physical Properties from Lithium to Kaliumfrom Lithium to Kalium
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ElementsElementsBoiling/Boiling/
MeltingMelting
PointPointDensityDensity
LiLi
NaNa
KK
RbRb
CeCe
Decrease
Changes in Physical Properties Changes in Physical Properties from Lithium to Potassiumfrom Lithium to Potassium
Increase
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PHYSICAL APPEARANCE
HARDNESS COLOR
• Grey• Soft ( easily cut with knife )
Lithium
Sodium
Potassium
Rubidium
Cesium
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Physical AppearancePhysical Appearance
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BOILING POINTMELTING POINT DENSITY
892 ºC98 ºC
766 ºC
2.1
63 ºC
181 ºC 1330 ºC
2.8.8.1
2.8.1
0.86g/cm3
0.53g/cm3
0.97g/cm3
Li
Na
K
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2.12.1
2.8.12.8.1
2.8.8.12.8.8.1
2.8.18.8.12.8.18.8.1
2.8.18.18.8.12.8.18.18.8.1
2.8.18.18.18.8.12.8.18.18.18.8.1
CONFIGURATIONS OF ELECTRON