Phase Change
Phase Change - Related Videos
07:59
Synthesis and Characterization of Multi-Modal Phase-Change Porphyrin Droplets
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Cited by 1 •
2021
In this protocol, methods for synthesizing and characterizing multi-modal phase-change porphyrin droplets are outlined.
02:39
Phase Diagrams
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2020
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
02:31
Phase Transitions
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2020
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to occupy...
08:14
Climate Change - Student Protocol
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2019
Melting Land and Sea Ice ExpandNOTE: This activity is a simulation of land- and sea-ice melting and their effects on water levels. First, label one graduated cylinder as 'Sea Ice' and the other graduated cylinder as 'Land Ice.' Hypotheses: the experimental hypothesis might be that the land ice melting will cause the water level to rise more than the melting sea ice. The null hypothesis would be that there will be no difference in the change in water level between the two containers. Add 10 ice...
04:34
Climate Change - Concepts
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2019
The certainty of climate change remains a public controversy despite the consensus among approximately 97% of active climate researchers, who not only agree that the Earth’s climate is changing but also state that this change is intensified by human activity, predominantly carbon emissions 1. The disconnect between the public and the experts is partly due to poor understanding of the mechanisms involved in climate change as well as the differences among essential concepts such as weather and...
FAQs
Energy supplied during a phase change is directed primarily into rearranging matter rather than immediately raising its temperature. This energy is called latent heat, meaning heat absorbed or released while the transition proceeds. Consequently, a material can remain at nearly constant temperature during melting, boiling, freezing, or condensation, so temperature alone does not fully indicate energy transfer.
Pressure alters the balance of intermolecular forces that maintains a material’s physical state. Changing pressure can therefore affect when matter transitions between states, even if its temperature is unchanged. This dependence is important in physics because temperature and pressure must be considered together when analyzing phase-change behavior, heat flow, and the thermodynamic performance of practical systems.
Intermolecular forces help hold particles in particular arrangements, so changing temperature or pressure can disturb that balance and produce a new state. The strength and balance of these forces determine how much energy must be absorbed or released during a transition. Studying this relationship connects microscopic interactions with observable melting, freezing, evaporation, condensation, and sublimation.
Transitions such as melting, evaporation, and sublimation absorb energy because the material moves toward a state requiring a different balance of intermolecular forces. The reverse processes, including freezing and condensation, release energy as that balance is re-established. This direction of energy flow helps physicists analyze thermal behavior and predict whether a process removes heat from or adds heat to its surroundings.
A basic investigation varies temperature or pressure while observing the material’s state and its thermal response. Researchers can track when a transition begins, whether the temperature remains steady during the change, and how much energy is absorbed or released. These observations reveal latent-heat behavior and connect measurable heat flow with the material’s thermodynamic transition.
Refrigeration exploits the heat absorbed or released during transitions such as evaporation and condensation. A material can absorb energy as it changes state and release that energy during the reverse transition, allowing heat to be transferred through a system. This makes phase-change principles central to controlling temperature and moving heat in refrigeration technology.
In power-generation systems, phase changes help explain how heat is transferred and how thermodynamic processes operate. Thermal energy storage uses the energy absorbed or released as a material changes state, allowing heat to be retained and later transferred. These applications rely on latent heat because substantial energy can move while the material’s temperature changes little.
Weather analysis uses phase changes to understand heat transfer associated with processes such as evaporation and condensation. Materials processing applies the same principles to control transformations including melting, freezing, and sublimation. In both contexts, identifying the transition and its energy exchange helps explain observed behavior, predict thermal effects, and manage how materials respond to changing conditions.