Question

write down the electronic configuration of the first three elements of group 1 what similarity do you find in their electronic configuration how many valence electrons are present in these three elements

Answer 1

hey
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•hydrogen =1 ( atomic no)

valence electron = 1

• helium= 2 ( atomic no)

electronic configuration = 2

valence electron =2

•lithium = 3 ( atomic no)

electronic configuration=2,1

valence electron = 1

in the first three groups in the first shell (k) they have maximum 1 and 2 electrons and maximum times atomic no is the electronic configuration itself

and in the valence shell they in hydrogen there is no valence electrons

hope helped
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Answer 2

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Element = Hydrogen  

Atomic Number = 1

Symbol Electron = H

Electronic Configuration = 1

Valence Electron = 1

Valency = 1

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Element = Helium  

Atomic Number = 2

Symbol Electron = He

Electronic Configuration = 2

Valence Electron = 2

Valency = 0

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Element = Lithium  

Atomic Number = 3

Electronic Configuration = (2,1)

Valence Electron = 1

Valency = 1

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