Two scales, one substance
Normal scale
Microscopic scale
Water · evolution of hydrogen bridges
Bridges drawn at this moment: · drawing indicator, without quantitative value for real water.
The solid lines connect O and H within a molecule. The blue dotted lines connect the H of one molecule to the O of another. Melting and boiling do not break O–H covalent bonds. The animation is significantly slowed down and does not reproduce the actual duration of the bridges.
State of substance
Conditions and scientific model
Pressure set to 101,325 Pa. The control imposes a temperature: no heating balance, reaction time or melting fraction is calculated. The volumes and proportions of the drawings are illustrative.
Water and hydrogen bridges: the ordered network of ice, its rearrangements in the liquid and the dispersion of molecules in the vapor are schematized in two dimensions. The H₂O molecules are bent (H–O–H angle of approximately 104.5° in the drawing). Up to two given bridges and two accepted are allowed per molecule; counting only concerns drawing. No calculation of molecular dynamics, binding energy or lifetime is carried out. The three-dimensional tetrahedral network and the rare associations in vapor are not resolved. IAPWS · ice structure and water properties ; RSC Advances · dynamic network of hydrogen bridges.
Pure substances have fusion and boiling marks. Oils and air are mixtures: their ranges are schematic and depend on the composition. Soda lime glass is amorphous and gradually softens. Sand is represented by pure silica, and plastic by LDPE.
The caramelization of sugar and the decomposition of oils or LDPE are chemical transformations. Once the degradation mark has been crossed, cooling does not recreate the initial material; “New sample” resets the simulation. The degradation thresholds are educational benchmarks, without calculated kinetics or reaction with oxygen.
Plasma of the nine initial pure bodies: estimation of first ionization of Saha, ideal gas at thermal equilibrium and simplified degeneration ratio. The dissociation beyond 2500 K is schematic. For the added materials, the extension at very high temperature qualitatively shows the gaseous products then their ionization: the graphic mark of 3,000 °C is not a boiling point. The ionization rate of these materials is not predicted. Colors do not represent an emission spectrum.
References: NIST · pure bodies ; IUPAC · Saha ; PubChem · sucrose ; PubChem · NaCl ; PubChem · silica.
Olive Oil Source · crystallization of oils ; MOL · melting and decomposition of LDPE ; Pilkington · properties of glass.