Tendancy of an atom to attract 𝐬𝐡𝐚𝐢𝐫𝐞𝐝 𝐩𝐚𝐢𝐫 𝐨𝐟 𝐞𝐥𝐞𝐜𝐭𝐫𝐨𝐧 in a covalent bond.
Factors on which 𝐞𝐥𝐞𝐜𝐭𝐫𝐨𝐧𝐞𝐠𝐚𝐭𝐢𝐯𝐢𝐭𝐲 𝐝𝐞𝐩𝐞𝐧𝐝𝐬
𝗦𝗶𝘇𝗲 𝗼𝗳 𝗲𝗹𝗲𝗰𝘁𝗿𝗼𝗻
Electronegativity       ∝          1/size
Means , when size is increase then Electronegativity decreases.
𝗡𝘂𝗰𝗹𝗲𝗮𝗿 𝗰𝗵𝗮𝗿𝗴𝗲
𝐄𝐥𝐞𝐜𝐭𝐫𝐨𝐧𝐞𝐠𝐚𝐭𝐢𝐯𝐢𝐭𝐲          ∝      𝐙
When atomic number(Z) is increases then electronegativity value is increases.
𝗖𝗵𝗮𝗿𝗴𝗲 𝗼𝗻 𝗮𝗰𝘁𝗶𝗼𝗻
Electronegativity      ∝      positive charge of Cation
When positive charge of Cation is increses then electronegativity of  atom is increases. 𝗖𝗵𝗮𝗿𝗴𝗲 𝗼𝗳 𝗔𝗻𝗶𝗼𝗻
Electronegativity    ∝     1/ negative charge of Anion
When negative charge of anion is increases then electronegativity of an action is decreases.
𝗛𝘆𝗯𝗿𝗶𝗱𝗶𝘇𝗮𝘁𝗶𝗼𝗻
When  % of ionic character in hybridization is increases then electronegativity of an atom is increases.
𝐇𝐲𝐛𝐫𝐢𝐝𝐢𝐳𝐚𝐭𝐢𝐨𝐧
sp(50%____50%)
sp2(33%___33%___33%)
sp3(25%___25%___25%____25%)
Then order of sp, sp2, sp3 in form of Increasing of hybridization.
sp >sp2 >sp3
𝗧𝗿𝗲𝗻𝗱𝘀 𝗼𝗳 𝗘𝗹𝗲𝗰𝘁𝗿𝗼𝗻𝗲𝗴𝗮𝘁𝗶𝘃𝗶𝘁𝘆 𝗶𝗻 𝗽𝗲𝗿𝗶𝗼𝗱𝗶𝗰 𝘁𝗮𝗯𝗹𝗲
𝗣𝗲𝗿𝗶𝗼𝗱 ( 𝗟--------->𝗥)
Electronegativity increases
𝗗𝗼𝘄𝗻 𝘁𝗵𝗲 𝗴𝗿𝗼𝘂𝗽
Electronegativity decreases because size increases.
𝗦𝗼𝗺𝗲 𝗲𝗹𝗲𝗺𝗲𝗻𝘁 𝗲𝗹𝗲𝗰𝘁𝗿𝗼𝗻𝗲𝗴𝗮𝘁𝗶𝘃𝗶𝘁𝘆 𝗶𝘀 𝗴𝗶𝘃𝗲𝗻 𝗯𝗲𝗹𝗼𝘄
𝗛 =𝟮.𝟭, 𝗖=𝟮.𝟱, 𝗡=𝟯,
𝗢=𝟯.𝟱, 𝗙=𝟰, 𝗣=𝟮.𝟭,
𝗦=𝟮.𝟱, 𝗖𝗹=𝟯, 𝗕𝗿=𝟮.𝟴,
𝗘𝗹𝗲𝗰𝘁𝗿𝗼𝗻𝗲𝗴𝗮𝘁𝗶𝘃𝗶𝘁𝘆 𝗱𝗲𝗰𝗿𝗲𝗮𝘀𝗲𝘀 𝗼𝗿𝗱𝗲𝗿
F>O>N/Cl>Br
Scales for measuring Electronegativity
Xa -Xb    =     √  Eab  --  √Eaa    × Ebb
Where, Xa = EN of a, Xb = EN of b, E = bond energy,
Formula is used when energy given in kcal/mole.
Mullicen scale
Electronegativity is the average of ionization energy and election affinity.

𝗘𝗹𝗲𝗰𝘁𝗿𝗼𝗻𝗲𝗴𝗮𝘁𝗶𝘃𝗶𝘁𝘆 =( 𝗜. 𝗘.    +    𝗘. 𝗔.) /𝟮

Application of Electronegativity

Nomenclature of Binory compound

The name of the compound who has more electronegativity is written later and put the (ide)together.
Example HCl,  H= 2.1,Cl= 3
So his name is hydrogen cloride

% of ionic character in Covalent bond

16 |∆x| + 3.5 |∆x|2
Where ∆x = Xa- Xb (difference of Electronegativity)

Bond strength ∝ Electronegativity difference

Metalic and non metalic character

Electronegativity High Non metal