When do Polar Covalent Bonds form

A polar covalent bond forms when the shared pair of electrons are more attracted to one atom than the other.This is due to the electronegativity difference between them.

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.

since electrons are negative the answer is neagtaive