Bond polarity Flashcards
What is electronegativity ?
The ability of an atom to attract the electrons in a covalent bond.
What is the scale of electronegativity ?
0.7 to 4
What happens to electronegativity as you go across a period ?
Increases across a period
What happens to electronegativity as you go up a a group ?
Increases as you go up a group
What group of atoms are electronegative and why ?
Group 7 are electron negative atoms because they have high electromagnetivity and can therefore attract electrons towards themselves.
What are atoms with low electronegativity called ?
Electropositive atoms.
What factors affect electronegativity ?
Shielding
Nuclear charge
Atomic radius
How does shielding affect electronegativity ?
The more orbitals the less electronegative charge as there is less attraction between the nuclear charge and the valence electrons
How does nuclear charge affect electronegativity ?
The greater the nuclear charge , the more electronegative charge because there is more attraction between the nuclear charge and electrons.
How does atomic radius contribute to electronegativity ?
The greater the nuclear charge, the smaller the atomic radius because the nuclear charge pulls some of the electrons in slightly.
Which is the most electropositive atom ?
Caesium
Which is the most electronegative atom ?
Fluorine
Draw a diagram showing the bond polarity between H-O
Notes
What is a polar covalent atom - definition ?
The electron distribution between elements with different electronegative charges will be unsymmetrical.
When do non-polar covalent bonds occur ?
If the electronegativity of both atoms in a covalent bonds is the same or very similar there will be no partial charge and therefore the bond will be non-polar.
