Vocabulary
Characteristic property: A quality of a substance that never changes and can be used to
identify the substance.
A characteristic property is a chemical or physical property that helps identify and
classify substances. The characteristic properties of a substance are always the same
whether the sample one is observing is large or small
Boiling point: the temperature at which a substance changes from a liquid to a gas
The temperature at which a liquid boils and turns to vapor
Melting point: the temperature at which a substance changes from a solid to a liquid
The temperature at which a given solid will melt
Physical change: a change in a substance that does not change its identity; for example, a
change of state.
- A change from one state (solid or liquid or gas) to another without a change in chemical
composition
Chemical activity: a characteristic property of substance that indicates it ability to
undergo a specific chemical change
Chemical change: a change in which on or more substances combine or break apart to form
new substances.
Chemical change is any change that results in the formation of new chemical substances.
At the molecular level, chemical change involves making or breaking of bonds between
atoms. These changes are chemical: iron rusting (iron oxide forms
Mixture: Two or more substances that are mixed together but not chemically combined
A product of mixing.
Any combination or blend of different elements, kinds, qualities, etc.:
Chemistry, Physics. An aggregate of two or more substances that are not chemically united
and that exist in no fixed proportion to each other
Solution: a very well-mixed mixture
Pure substance: a substance made of only on kind of matter and having definite properties
A pure substance is a sample of matter with both definite and constant composition with
distinct chemical properties
Element: a substance that cannot be broken down into other substances by chemical or
physical means.
each of more than one hundred substances that cannot be chemically interconverted or
broken down into simpler substances and are primary constituents of matter. Each element
is distinguished by its atomic number, i.e., the number of protons in the nuclei of its atoms.
Compound: a substance made of two or more elements chemically combined
A thing that is composed of two or more separate elements; a mixture.
A substance formed from two or more elements chemically united in fixed proportions.