How does atom electronegativity affect bond character and molecular polarity?

In case of heteroatomic molecules there is possibility of difference in electro negativity of the two hetero atoms bonded, this results in development of charges on the two atoms

more electronegative element will have a negative charge

less electronegative element will have a positive charge

Case

a) if the difference is less than 0.4 the molecule is  nonpolar.

b) if the difference is from 0.4 to 1.7 the molecule is  polar covalent.

c) if the difference is more than than 1.7 the molecule ionic (polar).

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.

the millers tale is the answer.