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sucess_seeker

If the electronegativity of the central atom decreases, how does bond angle decrease?

nunoxic

did u ever wonder y sp3 hybridized orbitals form a tetrahedron or sp2 form 120 degree angles ? or sp form 180 degree angles ?
cuz the lobes tend to repel each other and move as far as away from each other.......higher the electronegativity......higher is the repulsion......higher is the bond angle
Alternately ,
lower the electronegativity......lower is the repulsion......lower is the bond angle
*This can also be influenced by presence of lone pairs of electrons *

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coolfishamit

Well well well. This is one of my favorite concepts. To know this, lets take an example. suppose you have NH₃ and NF₃. Now i first case electro negativity is more and in second case it is less ( compared to H and F ) Now in first case, N being more electronegative pulls the shared pair of electrons towards itself. As a results all the atoms come close to a point (Nucleus) Since they are very close now the electrons in H atoms here would repel each other. The H which is attached to the N moves away from each other and so the bond angle increases.
Now in second case, F being more electronegative pulls the shared electrons towards ( Between F and N ) itself. As a result the shared pair of electrons move away from a common point (nucleus) in different directions. So due to less repulsions among themselves, they can exist close to each other. So the bond angle decreases

The point I'm trying to make is that in first case there is more electron density near nucleus. So the bonds having those electrons moves away from each other. In later case as the electron density is less the bonds don't need to move that way.

Hope u got it. Rate me dude

sucess_seeker

thanks everyone

Aatish

Consider an example of tug of war in which a single person is able to pull three other weaker persons towards him.........
As in the case of NH₃

And now consider another example of tug of war in which that same person is unable to pull three other persons (stronger) towards him.........
as in the case of NF₃The main concepts are already told by coolfishnishant and nunoxic......

Cheers...............

edison

Find your answer i the following link

http://www.chemguide.co.uk/atoms/bonding/electroneg.html

srijan88

LINUS PAULING IS THE FATHER OF THE CONCEPT OF ELECTRON SHIFT .........HE WAS THE PERSON WHO GAVE FOR THE FIRST TIME GAVE THE CONCEPTS OF ELECTRONEGATIVIY,HYBRIDISATION,AND THE VSEPR THEORY...............FOR THESE CONCEPTS HE WAS AWARDED THE NOBLE PRIZE .

SO IT MAKES SENSE TO THINK THAT WHY WOULD A PERSON DEVELOP THREE SEPARATE CONCEPTS IF THERE WAS NO NEED TO DO SO ....

ACTUALLY THE HYBRIDISATION OF THE CENTRAL ATOM HAS NOTHING TO DO WITH ITS ELECTRONEGATIVITY........HOWEVER IT WAS SHOWM BY MULLIKEN (FOR THIS HE WAS AWARDED THE NOBLE PRIZE IN 1966)

THAT THE ELECTRONEGATIVITY OF DIFFERENT ATOMS IN DIFFERENT HYBRIDISED STATES IS DIFFERENT ...........

THIS IS EXPLAINED BY THE INCREASE IN PENETRATION WITH THE INCREASE IN s -CHARECTER OF AN ORBITAL............

AND REMEMBER ELECTRONEGATIVITY IS AN INHERENT PROPERTY OF AN ELEMENT AND IT HAS NOTHING TO DO WITH THE LONE PAIRS OR BOND PAIRS OF ELECTRONS AN ELEMENT HAS.....

SO DON'T USE THE VSEPR THEORY IN ELECTRONEGATIVITY......

ALSO THE MORE ELCTRONEGATIVE ATOM DOES NOT ATTRACT THE PIE ELECTRONS OF ITS ADJACENT ATOMS ...........

ELECTRONEGATIVITY IS CONFINED TO THE SIGMA BOND ONLY.........

HOPE I WAS ABLE TO CLEARIFY ALL YOUR DOUBTS...........

BY THE YOU CAN GET LINUS PAULING'S THESIS ............"THE NATURE OF THE CHEMICAL BOND"

IT'S VERY VERY POPULAR ....YOU WILL FIND IT IN ANY PUBLIC

LIBRARY...

sucess_seeker

thanks for the electronegativity concept related to pie bond.

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