The document discusses alkali metals and alkaline earth metals. Alkali metals such as lithium, sodium, and potassium are placed in Group 1A of the periodic table and have one electron in their outermost shell. They react violently with water to form strong alkali hydroxides and hydrogen gas. Alkaline earth metals like beryllium, magnesium, and calcium are in Group 2A and have two outer electrons. They are less reactive than alkali metals but still react with water and acids to produce hydrogen. The reactivity of both groups increases down the respective groups.

1. Topic: Alkali metals and AlkalineTopic: Alkali metals and Alkaline
metalsmetals
AKM A- FormAKM A- Form
Chapter - Metallurgy
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2. Alkali MetalsAlkali Metals
The elements such as Lithium (Li), sodiumThe elements such as Lithium (Li), sodium
(Na), potassium(K), rubidium(Rb),Cesium(Na), potassium(K), rubidium(Rb),Cesium
(Cs) and francium(Fr) have one electron in(Cs) and francium(Fr) have one electron in
their outermost shelltheir outermost shell so they are placed in IAso they are placed in IA
group of the periodic table.group of the periodic table.
They react with water to form their hydroxidesThey react with water to form their hydroxides
which are strong alkalis.which are strong alkalis.
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3. Position of Alkali metals in groupPosition of Alkali metals in group
IAIA
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4. Characteristics of alkali metalsCharacteristics of alkali metals
1.Occurance : All of them are very reactive and
do not occur in free state.
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5. Characteristics of alkali metalsCharacteristics of alkali metals
 2. Nature: They are soft and can be cut with a2. Nature: They are soft and can be cut with a
knife and have low melting and boiling points.knife and have low melting and boiling points.
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6. Characteristics of alkali metalsCharacteristics of alkali metals
3. Bonding: All alkali metal salts are ionic in3. Bonding: All alkali metal salts are ionic in
nature.nature.
e.g. NaCl, KBr, LiCl,e.g. NaCl, KBr, LiCl,
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7. Characteristics of alkali metalsCharacteristics of alkali metals
4. Action of Air : They react rapidly with oxygen4. Action of Air : They react rapidly with oxygen
and water vapour in the air. Reactivityand water vapour in the air. Reactivity
increases down the group.increases down the group.
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8. Characteristics of alkali metalsCharacteristics of alkali metals
5.Action of water: They react violently with5.Action of water: They react violently with
water and produce hydrogen.water and produce hydrogen.
2M + H2M + H22OO  2MOH + H2MOH + H22
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9. Characteristics of alkali metalsCharacteristics of alkali metals
6.Action of acids: They react violently with acids, dil6.Action of acids: They react violently with acids, dil
HCl and Dil HHCl and Dil H22SOSO44 to produce hydrogen gas.to produce hydrogen gas.
2M + 2HCl2M + 2HCl  2MCl +H2MCl +H22
C
L
I
C
K
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10. Alkaline Earth MetalsAlkaline Earth Metals
 The elements such as Beryllium, magnesium,The elements such as Beryllium, magnesium,
calcium, strontium and barium and radium are knowncalcium, strontium and barium and radium are known
as alkaline earth metals because their oxides occur inas alkaline earth metals because their oxides occur in
the earth’s crust and their hydroxides are alkalies.the earth’s crust and their hydroxides are alkalies.
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11. Characteristics of Alkaline earthCharacteristics of Alkaline earth
metalsmetals
1.Occurrence: They are reactive1.Occurrence: They are reactive
metals (less reactive than alkalimetals (less reactive than alkali
metals); hence they also do notmetals); hence they also do not
occur in free in nature.occur in free in nature.
They have two electrons in theirThey have two electrons in their
last shell so they are placed inlast shell so they are placed in
group IIA of the Periodic table.group IIA of the Periodic table.
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12. Alkaline Earth MetalsAlkaline Earth Metals
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13. Characteristics of Alkaline earthCharacteristics of Alkaline earth
metalsmetals
2.Nature: They are grayish white in colour and2.Nature: They are grayish white in colour and
harder than alkali metals.harder than alkali metals.
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14. Characteristics of Alkaline earthCharacteristics of Alkaline earth
metalsmetals
 3.Bonding: All the alkaline earth metal salts3.Bonding: All the alkaline earth metal salts
except beryllium are ionic compounds.except beryllium are ionic compounds.
e.g. MgO, CaCle.g. MgO, CaCl2,2, MgClMgCl2.2.
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15. Characteristics of Alkaline earthCharacteristics of Alkaline earth
metalsmetals
4.Action of air: They are less reactive than alkali4.Action of air: They are less reactive than alkali
metals.metals.
Their reactivity increases on moving down theTheir reactivity increases on moving down the
groupgroup
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16. Characteristics of Alkaline earthCharacteristics of Alkaline earth
metalsmetals
5.Action of water: They react with water to5.Action of water: They react with water to
produce hydrogen.produce hydrogen.
M + 2HM + 2H22OO  M(OH)M(OH)22 + H+ H22
M is any alkaline earth metal. Ba reacts mostM is any alkaline earth metal. Ba reacts most
vigrously with water.vigrously with water.
Click
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17. Characteristics of Alkaline earthCharacteristics of Alkaline earth
metalsmetals
 6. Action of acids: They react with dil HCl and6. Action of acids: They react with dil HCl and
dil Hdil H22SOSO44 to produce hydrogen.to produce hydrogen.
M + 2HClM + 2HCl  MClMCl22 + H+ H22
M + HM + H22 SOSO44  MSOMSO44 + H+ H22
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18. AssessmentAssessment
 1. Why are alkali metals kept in water?1. Why are alkali metals kept in water?
 2. Which metal reacts with cold water2. Which metal reacts with cold water
violently?violently?
 3. Alkali metal salts are _________3. Alkali metal salts are _________
(ionic/covalent) in nature.(ionic/covalent) in nature.
4. Reactivity of alkali metals ____________4. Reactivity of alkali metals ____________
down the group (increases/decreases/remainsdown the group (increases/decreases/remains
same)same)
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