Why is uranium hexafluoride useful for uranium enrichment?

Uranium hexafluoride (${\text{UF}}_6$) is essential for uranium enrichment because it is a volatile compound that can easily be converted into a gaseous state. This property is critical for the primary methods used to separate the fissile isotope uranium-235 from the more abundant uranium-238.1234

In gaseous diffusion, ${\text{UF}}_6$ gas is passed through a porous barrier. Because molecules containing the lighter ${}^{235}\text{U}$ isotope travel at a higher velocity than those containing the heavier ${}^{238}\text{U}$, they traverse the barrier more rapidly, allowing for gradual enrichment.34

Similarly, in gas centrifugation, ${\text{UF}}_6$ gas is spun at high speeds. The heavier ${}^{238}{\text{UF}}_6$ molecules accumulate along the walls of the centrifuge, while the lighter ${}^{235}{\text{UF}}_6$ molecules concentrate near the center, enabling the two isotopes to be siphoned off separately. Without the ability to transform uranium into this volatile gaseous form, these standard industrial enrichment processes would not be possible.412