bond polarity

electronegativity

the power of an atom to attract a pair of electrons in a covalent bond

factors affecting electronegativity?

• nuclear charge- more protons, more stronger attraction between nucleus and bonding pair of electrons

• atomic radius- closer to nucleus, stronger attraction between nucleus and bonding pair of electrons

• shielding- less shells of electrons ( less repulsion) stronger attraction between nucleus and bonding pairs of electrons

electronegativity trend in periodic table

Across groups

Up period

going down does what to the nuclear charge

increases it

what do differences in electronegativity lead to?

polar bonds

polar bond

is a covalent bond in which there is a seperation of charge between one and another

draw a bond between two hydrogen and chlorine

What happens when its diatomic?

no polar bond

what determines a polar or non polar molecule

shape of molecule

what happens when charges cancel out?

non polar molecule

if they don’t cancel?

polar molecule

what happens between carbon and hydrogen?

no polar bonds

what does electron density suggest

how negative charge is distributed in a molecule

what scale is used to measure electronegativity?

Pauling scale

what happens when its a smaller atom?

the closer the nucleus is to the outer electron shell and the greater the electronegativity

what happens with a greater nuclear charge?

the greater the electronegativity

what happens going up a table?

electronegativity increases as the atoms get smaller and there is less shielding

what happens going across

the electronegativity increases, the nuclear charge increases, shielding remains same, atoms get smaller

where are the most electronegative atoms found

top right corner

polarity simple words

unequal sharing of electrons between atoms

what happens when atoms are different

different electronegativity, the more electronegative side has a slighter negative , electrons are not shared equally, cloud of charge is more towards the electronegative side. Polar molecule

the greater the difference in electronegativity…

the more polar the molecule

what is the most and least electronegative element in Pauling scale?

most- F

least- Cs

What does a large difference in electronegativity result in?

an ionic compound

what is the overall polarity of a molecule called?

dipole