What is the general minimum initial mass threshold required for a star to become a Type II supernova progenitor?
Answer
Greater than about eight times the mass of the Sun ($8 M_{\odot}$)
Stars generally considered to be those starting with masses greater than about eight times the mass of the Sun are the ones that undergo core collapse to become Type II supernovae.

Related Questions
What state does a low-mass star, like our Sun, eventually settle into after exhausting its core hydrogen?What is the general minimum initial mass threshold required for a star to become a Type II supernova progenitor?What process triggers the catastrophic collapse leading to a Type II supernova?What is required for a white dwarf remnant to cause a Type Ia supernova explosion?What quantum mechanical effect primarily supports a white dwarf against gravitational collapse?What remnant is typically left after a Type II (core-collapse) supernova?Why can a star with a mass similar to the Sun not become a Type II supernova progenitor?Approximately what mass does a white dwarf approach in a binary system to trigger a Type Ia supernova?What fundamental difference distinguishes the initiating force of a Type Ia event from a Type II event?What is the eventual fate of the Sun?What pressure momentarily halts the collapse after the iron core implosion in a massive star, leading to a Type II explosion?