deliquescence (dĕlˌəkwĕsˈəns) [key], conversion of a solid substance into a liquid as a result of absorption of water vapor from the air. Since impurities in a solid lower its melting point, the absorbed water causes a decrease in the normal melting point of the solid. If enough water is absorbed to lower the melting point below room temperature, the solid will deliquesce, or turn to liquid. Lithium sulfide and magnesium iodide are examples of deliquescent salts.
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