Electronegativity and polarity Flashcards
What is electronegativity?
A measure of the attraction of a bonded atom for a pair of electrons in a covalent bond.
How is electronegativity measured?
The pauling scale
What is the trend of electronegativity across and up the periodic table?
Increases
Why does the electronegativity increases across and up the periodic table?
The nuclear charge increases.
The atomic radius decreases.
What does a large pauling value indicate?
It is very electronegative.
Which group is the least electronegative?
Group 1
What is a non-polar bond?
Where the bonded electron pair is shared equally between bonded atoms
What conditions are needed for a bond to be non-polar?
The bonded atoms are the same or have the same/similar electronegativites.
What is a polar bond?
Where the bonded electron pair is shared unequally between the bonded atoms.
What conditions must there be for a bond to be polar?
The bonded atoms are different and have different electronegativity values.
What is a dipole?
A separation in electrical charge so that one atom of the polar covalent bond is positive has a small positive charge and the other a small negative charge.
What is a dipole in a polar covalent bond?
Permanent dipole
