No substance can exist in the liquid state at____________________?
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Answer: C. zero pressure
Explanation
Liquid phase stability requires minimum molecular cohesion and confining pressure. At zero pressure, molecules lack the necessary surrounding pressure to remain condensed. Substances transition directly from solid to gas without forming a liquid. Phase diagrams map out the pressure and temperature boundaries for states. The triple point is the lowest pressure where all three phases coexist. Absolute zero pressure removes all intermolecular forces holding fluids together.
Outer space environments feature extremely low pressures preventing liquid water existence. Industrial vacuum chambers must account for phase changes at reduced pressures. Astrophysicists study phase behavior under extreme cosmic pressure conditions. Option A represents a temperature limit rather than a zero pressure condition. Option B vacuum still contains extremely low residual pressure in practice. Options D and E can still sustain high pressures allowing liquid states.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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