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group IA

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Rayan:
hello.
i just want to know why do elements of group IA (H-Li-Na...) react vegorously with water.
thanks.

Grafter:
All of the group 1 metals have one electron in their outer shell. This makes it very easy to remove.
How do you think this relates to their ability to react with water?
Which will react most quickly out of Li, Na and K?
Can you write out a balanced equation for the reaction with water?

Na + H2O --> ?

Rayan:
starting from what you said, since they all have one electron in the outer shell, and since it is easy to remove, then it will be even easier to remove this electron if it's far away from the nucleus because then it will be less attracted to it. then i think that K will react most quickly with water.
as for the balanced equation, i'm not sure but i think:

Na + 2H2O --> NaOH + 1/2 H2

waiting your reply as soon as possible. thank you

Grafter:
Nearly,

Na + H2O --> NaOH + 1/2 H2

Can you write out the half equations for the reaction?
Which will be a more alkaline solution, LiOH, NaOH or KOH?
Will this reaction happen for group II metals in the same way? What will the products be?

Rayan:
The half equations for the reaction are:

Na ---> Na+ + 1e

2H2O + 2e---> 2HO- + H2

(The first equation should be multiplied by 2 when writing the overall reaction.)

Li ---> Li+ + 1e

2H2O + 2e---> 2HO- + H2


K ---> K+ + 1e

2H2O + 2e---> 2HO- + H2

Ca ----> Ca2+ + 2e

2H2O + 2e---> 2HO- + H2

I can't see the difference between these reactions!
They seem to be the same for me. But I know that Li reacts slowly, Na reacts vigorously, K reacts violently. As for Ca, it reacts quite quickly. I know this because we learned it but I dont know why!
I need help.

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