Chemistry Polarity and IMF Quiz

Nonpolar bonds

When the atoms in a bond are the same element

• Electrons are shared equally 

Polar bonds

when two different atoms are in a bind

• Electrons may not be shared equally

• The bigger the electronegativity difference between the elements, the more polar the bond is

How to show polar bonds

A dipole is used to show a partial charge 

• δ+ means partially positive 

• δ- means partially negative 

• Arrow is used to point in the direction of the greater electron density (atom with more electronegativity)

Polar molecules 

• Molecules have a positive and negative end 

• If the molecule has a lone pair on the central atom → polar overall

• If the molecule has no lone pairs and the outer atoms are different → polar overall 

• If the molecule has no lone pairs and all the outer atoms are the same → nonpolar overall

Intramolecular forces

the forces within a molecule 

• Ex: the bonds

Intermoleculular forces

the forces between any two molecules 

• Much weaker than covalent bonds 

London forces of attraction

•  (van der wall forces)

  • Electrons may create a temporary dipole (partial charge) on the atom due to constant movement 

  • Weakest of all forces

  • Found between all molecules (polar and nonpolar)

Dipole-Dipole force of attraction 

• Found in addition to London forces in molecules that are polar (already polar) 

  • Negative dipole attracts to positive

Hydrogen bonding 

• Occurs in molecules that have an H bonded to an F, O, or N → H needs to be directly attached to either F, O or N

  • Attraction between dipoles (Negative dipole attracts to positive)