<Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (November 2011) (Learn how and when to remove this template message) </Td> </Tr> <P> Physical changes are changes affecting the form of a chemical substance, but not its chemical composition . Physical changes are used to separate mixtures into their component compounds, but cannot usually be used to separate compounds into chemical elements or simpler compounds . </P> <P> Physical changes occur when objects or substances undergo a change that does not change their chemical composition . This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances . In general a physical change is reversible using physical means . For example, salt dissolved in water can be recovered by allowing the water to evaporate . </P> <P> A physical change involves a change in physical properties . Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density . </P>

What do you mean by physical change and chemical change
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