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A number of materials contract on heating within certain temperature ranges; this is usually called negative thermal expansion, rather than "thermal contraction".For example, the coefficient of thermal expansion of water drops to zero as it is cooled to 3.983 °C (39.169 °F) and then becomes negative below this temperature; this means that water has a maximum density at this temperature, and ...
Temperature gradients, thermal expansion or contraction and thermal shocks are things that can lead to thermal stress. This type of stress is highly dependent on the thermal expansion coefficient which varies from material to material. In general, the greater the temperature change, the higher the level of stress that can occur.
The law was named after scientist Jacques Charles, who formulated the original law in his unpublished work from the 1780s.. In two of a series of four essays presented between 2 and 30 October 1801, [2] John Dalton demonstrated by experiment that all the gases and vapours that he studied expanded by the same amount between two fixed points of temperature.
The rubber band experiment can be modeled as a thermodynamic cycle as shown in the diagram. The stretching of the rubber band is an isobaric expansion (A → B) that increases the energy but reduces the entropy (this is a property of a rubber bands due to rubber elasticity). Holding the rubber band in tension at ambient temperature is an ...
Ring expansion and ring contraction reactions expand or contract rings, usually in organic chemistry. The term usually refers to reactions involve making and breaking C-C bonds, [1] Diverse mechanisms lead to these kinds of reactions. The bond migration step of the pinacol type rearrangement
The metals involved in a bimetallic strip can vary in composition so long as their thermal expansion coefficients differ. The metal of lower thermal expansion coefficient is sometimes called the passive metal, while the other is called the active metal. Copper, steel, brass, iron, and nickel are commonly used metals in bimetallic strips. [6]
Lavoisier argued that this “igneous fluid” is the cause of heat, and that its existence is necessary to explain thermal expansion and contraction. When an ordinary body—solid or fluid—is heated, that body ... occupies a larger and larger volume. If the cause of heating ceases, the body retreats ... at the same rate as it cools.
The Joule expansion, treated as a thought experiment involving ideal gases, is a useful exercise in classical thermodynamics. It provides a convenient example for calculating changes in thermodynamic quantities, including the resulting increase in entropy of the universe ( entropy production ) that results from this inherently irreversible process.