* Van der Waals forces: Helium, like all substances, exhibits weak intermolecular forces known as Van der Waals forces. These forces are responsible for helium's ability to condense into a liquid at extremely low temperatures.
* Isotopes: Helium exists in two stable isotopes, Helium-3 and Helium-4, with slightly different nuclear properties.
* Excitation: Helium can be excited to higher energy states by absorbing photons or colliding with other particles. This excitation can lead to the emission of light, as seen in helium-neon lasers.
* Rare Compounds: While rare, helium can form compounds under extreme conditions. For example, HeNa2 has been observed at high pressures.
The key takeaway is that while helium's chemical properties are very limited compared to most elements, it's not entirely devoid of them. Saying it has *no* chemical properties would be an oversimplification.
