Explain: why `N_(2)" and "F_2` are non-polar and HF is polar?

Explanation

`N_(2)" and "F_2` are the homoatomic molecules and the eletronegativity differnce between the atoms of N and F is zero. Therefore, `N_(2)" and "F_2` are non-polar. On the other hand , HF is a heteroatomic molecule. Both the atoms H and F have different electronegativity values. therefore, the electronegativity difference between the atoms of H and F is not zero. hence, HF is polar in nature.