During collapse progression, what temperature is required for molecular hydrogen ($ ext{H}_2$) to dissociate?
About $2000 ext{ K}$
As a contracting core of gas advances past the stage of the first hydrostatic core, it continues to heat up due to the infall of material. A crucial step in allowing the collapse to resume on a slower timescale involves the behavior of the molecular hydrogen ($ ext{H}_2$). When the core temperature reaches approximately $2000 ext{ Kelvin}$, the kinetic energy becomes high enough to cause the molecular hydrogen to break apart into atomic hydrogen. This dissociation process acts as an energy sink, absorbing a significant portion of the contraction energy that would otherwise be converted into thermal pressure. By absorbing this energy, the pressure increase is temporarily mitigated, allowing the overall gravitational collapse to continue past this point until subsequent heating stages, like atomic ionization, occur.
