AQA A-Level Chemistry: Electronegativity and Polarity

is the less electronegative element in a covalent bond known to have a partial negative or a partial positive charge?

a partial positive charge

why are the electrons described as an electron cloud?

because the electrons orbiting the nucleus of an atom move so fast that they generate an electron cloud

what does it mean for a molecule to be unsymmetrical?

different atoms, or atoms and lone pairs, around the central atom

what is the most electronegative element?

fluorine

are symmetrical molecules polar or non-polar?

non-polar

is an element with the same element covalently bonded to each other polar or non-polar and why? (like Cl2)

non-polar because the electronegativity of each Cl atom is equal.

are unsymmetrical molecules polar or non-polar?

polar

is HCl polar or non-polar and why?

polar because chlorine is much more electronegative than hydrogen, meaning chlorine pulls more electron density to itself.

what type of bond does electronegativity concern?

simple covalent

define electronegativity

the ability of an atom to attract electron density from a covalent bond

the better an atom is at attracting electrons towards itself....

the more electronegative it is

the closer an element is to fluorine....

the more electronegative it is

the greater the difference in electronegativity....

the more polar the bond is

what does it mean for a molecule to be symmetrical?

the same atom around the central atom

what is the trend in electronegativity (and reasons for the trend) similar to?

trends in ionisation energy

what are the three factors which determine how electronegative an element is?

- nuclear charge, atomic radius and electron shielding