Biology Biomolecules ETEA 2023 Retake
PMDC Verified Question 44 of 142
All are the properties of water excluding:
A
Universal solvent
B
Polar nature
C
Becomes dense when it freezes
D
Hydrogen bonding
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: Becomes dense when it freezes
Concept:

Water has one profound, life-saving physical anomaly regarding its solid state.

Solution:

  • Nearly all substances in the universe become denser as they transition from a liquid to a solid because molecular kinetic energy drops, allowing molecules to pack tighter.


  • Water is the stark exception. As it approaches freezing (below 4°C), its hydrogen bonds lock into a rigid, open-spaced hexagonal crystal lattice.


  • This vast empty space in the lattice means ice is strictly less dense than liquid water, allowing it to float.


  • Therefore, the claim that it "becomes dense when it freezes" is physically false.


Why other options are incorrect (they are true properties of water):

  • Universal solvent & Polar nature: Driven by its dipole moment.


  • Hydrogen bonding: The core force defining its behavior.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Previous Question All Biomolecules MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App