Is H2 Polar or Nonpolar?

Answer: H2 is a nonpolar molecule because electrons are dispersed equally throughout this linear molecule.

Although temporary imbalances may occur with small London Dispersion forces, the fact that H2 only has two electrons makes these rare occurrences and inconsequential when considering intermolecular forces.

Considering the question from the angle of electronegativity (of 2.20), one sees that the two hydrogens have the same electronegativity and therefore have the same pull on the electrons, causing the molecule to be nonpolar.

H2 Molecule Ball and Stick
H2 Molecule Ball and Stick Model. Created with Avagadro.

Does this mean that H2 is not reactive?

Since hydrogen does not have a full valence shell, it will form bonds easily with many different elements (ex. H2O and HF). When diatomic hydrogen comes in contact with other elements, it may react quite violently in order to form a bond with the new element. These kinds of reactions are the reason for the Hindenburg Disaster of 1937 which underscored the fact that helium cannot simply be replaced by hydrogen (H2) even thought the latter is a cheaper and more widely available resource. Helium is much stabler element because it has a full valence shell as a noble gas. On the flip side, the reactivity of H2 has allowed it to become a principle component on some fuel systems [1].

Various uses of hydrogen flowchart
Various uses of hydrogen. Source

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