Chemistry Chapter 1 Textbook

physical process

transformation of a sample of matter that does not alter the chemical identities of any of the substances in the sample (ex. solid to liquid)

two principle classes of matter

pure substances and mixtures

pure substance is a ___ or an ___

compound, element

elements of a compound can be separated by a ___

chemical reaction (transformation of one or more substances into one of more different substances)

macroscopic property

can observe without considering the atomic or molecular scale of matter

particulate representation

focuses on the composition of matter

mixture

form of matter that is composed of two or more substances that retain their own chemical identities (substances are not in definite proportions; can be separated by physical processes)

homogeneous mixtures are also called ___

solutions

molecules are held by ___

chemical bonds

law of constant composition

every sample of a compound always contains the same elements combined in the same proportions

diatomic molecules

two atom molecules (ex. N2, O2)

ions

positively and negatively charged particles that are electrostatically attracted to one another; may consist of single atoms or two or more atoms bonded together that have an overall positive or negative charge