Question bank — States of matter — solid, liquid, gas, plasma; macroscopic vs particulate view

False — they vibrate about fixed lattice sites (~$10^{13}$ Hz), and even at 0 K quantum zero-point energy keeps them jiggling; only translational wandering is absent.

True — with negligible Intermolecular Forces, particles fly apart until walls stop them, so both shape and volume are set entirely by the container.

True — both are "condensed" states with particles touching, so their densities are comparable, unlike a gas which is roughly 1000× less dense.

False — some solids sublime directly to gas (e.g. dry ice, iodine) when the pressure sits below the substance's triple point; on the $P$–$T$ phase map (Figure s02) the state simply crosses the solid→gas line with no liquid region in between.

False — heating a gas enough ionizes it, stripping electrons off atoms so the substance now contains free charges; unlike a neutral gas, plasma conducts electricity and bends to magnetic fields, so its behaviour is genuinely different, not just hotter.

False — liquids resist compression because their particles are already touching (electron-cloud repulsion), while gases compress because there is vast empty space between particles to squeeze out.

True — since $⟨KE⟩=\frac{3}{2}{k}_{B}T$ depends only on $T$, both phases at one temperature share the same average kinetic energy; they differ in potential energy (how deep in the IMF well they sit), not kinetic.

False — a liquid flows while IMF are still active but transient; bonds constantly break and reform (H-bond lifetime ~1 ps in water), so net rearrangement is easy without full separation.

The error is conflating type with amount of motion; solids vibrate (no translation), liquids add translation/rotation, gases are free translation — it's about which modes are unlocked, not just speed.

Wrong — liquids have short-range order: each molecule keeps a preferred coordination shell of neighbours (the cage in Figure s01) that decays over ~2–3 diameters; only long-range crystalline order is missing.

It assumes negligible IMF and negligible particle volume; it fails at high pressure or low temperature where particles crowd and attract, so real gases deviate (that's why Gas Laws add attraction and volume correction terms, as in van der Waals).

Distance does not set temperature — since $⟨KE⟩=\frac{3}{2}{k}_{B}T$, temperature tracks speed; fast compression heats the gas because your piston does work on the molecules, speeding them up, not because they got closer.

The molecules are identical mass — ice floats because H-bonds force an open hexagonal lattice that spaces molecules farther apart than in liquid water, lowering density, not mass.

Density is low because of huge spacing (~10× particle diameter apart), not small particles; the same molecules packed in the liquid are dense.

Its particles still touch and resist being pulled apart (fixing volume) but are not locked into a lattice, so they slide past one another and conform to any container (indefinite shape).

Higher $T$ raises the escape probability $P\propto e^{-E_{IMF}/k_{B}T}$ (Figure s01): more particles carry enough kinetic energy to climb out of the well of depth $E_{IMF}$ and leave their cage, easing flow — same escape idea drives Evaporation and Boiling.

Because whether particles stay bound depends on motion energy compared to the attraction strength $F_{IMF}$; the same $KE$ gives a solid for a strongly-bonded substance and a gas for a weakly-bonded one.

Once particles contact, further compression must overcome electron-cloud repulsion (a very steep energy wall), so incompressibility comes from repulsion, not from bonds.

Countless particles collide with the container walls; each collision transfers momentum ($\Delta p=2m{v}_x$), and the summed force per unit area over many collisions is what we measure as pressure (from Kinetic Molecular Theory).

The macroscopic view describes bulk behaviour (flows, holds shape), while the particulate view explains it; chemistry is the constant translation between what we see and what particles are doing.

No — quantum zero-point energy guarantees residual vibration; classical KMT predicts zero motion, but reality keeps particles jiggling even at absolute zero.

Not for amorphous solids (glass, some plastics) — they lack a crystal lattice and soften gradually over a range, so no single sharp melting point exists, unlike crystalline solids.

No — they are the four everyday ones; liquid crystals (mesophases) flow like a liquid yet keep the molecules pointing the same way like a solid, and in extreme labs Bose–Einstein condensates (near 0 K) and degenerate matter (in dead stars) behave as further distinct states.

Yes — above the critical point the two phases merge into a supercritical fluid with no meniscus; on the phase map (Figure s02) the liquid–gas line simply ends at that point, so you can travel from liquid to gas continuously by looping around it.

In the plasma state — stars are enormous ionized-gas bodies, so plasma is the most common visible state cosmically even though it's rare on Earth's surface (see Plasma in Stars).

The "$F_{IMF}$ negligible" assumption breaks: slower particles linger near each other long enough for attractions to matter, they clump, and the gas condenses to liquid — the model must be abandoned there.

Not necessarily — strong electric fields or radiation can ionize a gas at modest temperature (e.g. neon signs, fluorescent tubes), so plasma is defined by ionization, not solely by heat.