Electronegativity-bond polarity

Electronegativity

The power of an atom to attract electrons towards itself in a covalent bond

Trend of electronegativity down the group

Decreases

Trend of electronegativity down a period

Increases from left to right

What does electronegativity depend on

The nuclear charge

Distance between the nucleus and the outer electrons

Shielding done by electrons in inner shells

How does nuclear charge influence electronegativity

The larger the charge, the greater the electronegativity

How does size of the atom affect electronegativity

The smaller the atom, the closer the nucleus is to the shared electrons causing electronegativity to increase

Polarity

The unequal sharing of the electrons between atoms

Non polar

Electrons shared equally

Polar

Electrons shared unequally

What is the distribution of electron density in non polar molecules

Symmetrical

What is the distribution of electron density in polar molecules

Not symmetrical

Polar covalent bond

When electrons are shared unequally creating a partial negative charge δ- and partially positive charge δ+

Net dipole moment

Overall polarity of the entire molecule

How do you know that there is no net dipole moment

When all dipoles cancel each other out and point outwards. The structure is symmetrical

How do you know that there is a net dipole moment

When all the dipole point inwards and do not cancel out. The structure is asymmetrical