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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