Polar Covalent Bonds and Polar Molecules (HSC SSCE Chemistry): Flashcards

Polar covalent bonds

Covalent bonds with unequally shared electrons

What $\delta^+$ and $\delta^-$ represent

Partial charges, smaller than full electron/proton charges

Electronegativity

Atom's ability to attract bonding electrons towards itself

Dipole

Equal but opposite charges separated in space

Polar molecules

Molecules with a net dipole that doesn't cancel out

How molecular shape affects polarity

Determines if dipoles add up or cancel out

$\text{H}_2\text{O}$ polarity and shape

Polar; bent shape causes dipoles to add, not cancel

$\text{CH}_4$ polarity

Non-polar; tetrahedral shape makes dipoles cancel completely

Most electronegative element

Fluorine

Two steps to determine if molecule is polar

1. Identify polar bonds 2. Check if dipoles cancel via shape