(a) Copper and nitric acid undergo a chemical change to form copper nitrate and brown, gaseous nitrogen dioxide. In each of these examples, there is a change in the physical state, form, or properties of the substance, but no change in its chemical composition. Other examples of physical changes include magnetizing and demagnetizing metals (as is done with common antitheft security tags) and grinding solids into powders (which can sometimes yield noticeable changes in color). We observe a physical change when wax melts, when sugar dissolves in coffee, and when steam condenses into liquid water ( ). A physical change is a change in the state or properties of matter without any accompanying change in its chemical composition (the identities of the substances contained in the matter). Other physical properties, such as the melting temperature of iron or the freezing temperature of water, can only be observed as matter undergoes a physical change. We can observe some physical properties, such as density and color, without changing the physical state of the matter observed. Familiar examples of physical properties include density, color, hardness, melting and boiling points, and electrical conductivity. A physical property is a characteristic of matter that is not associated with a change in its chemical composition. The characteristics that enable us to distinguish one substance from another are called properties.
When a material changes from a solid to a liquid to a vapor it seems like them become a difference substance. The difference between a physical and chemical property is straightforward until the phase of the material is considered.
Flammability and corrosion/oxidation resistance are examples of chemical properties. Properties that describe how a substance changes into a completely different substance are called chemical properties. The general properties of matter such as color, density, hardness, are examples of physical properties. Physics of Nondestructive Evaluation > Materials and Processes > Physical and Chemical Properties Physical and Chemical PropertiesPhysical properties are those that can be observed without changing the identity of the substance.
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