2Chem10: Unit 1 ~ Matter and Change

science

the knowledge obtained by observing natural events and conditions in order to discover facts and formulate laws or principles that can be verified or tested

chemistry

the scientific study of the composition, structure, and properties of matter and the changes that matter undergoes

chemical

any substance that has a defined composition

mass

a measure of the amount of matter in the object

matter

anything that has mass and takes up space

atom

the smallest unit of an element that maintains the chemical properties of that element

element

a substance that cannot be separated or broken down into simpler substances by chemical means; all atoms of an ___ have the same atomic number

compound

a substance made up of atoms of two or more different elements joined by chemical bonds

extensive property

a property that depends on the extent or size of system

intensive property

a property that does not depend on the amount of matter present, such as pressure, temperature, or density

physical property

a characteristic of a substance that does not involve a chemical change, such as density, color, or hardness

physical change

a change of matter from one form to another without a change in chemical properties

change of state

the change of a substance from one physical state to another

solid

the state of matter in which the volume and shape of a substance are fixed

liquid

the state of matter that has a definite volume but not a definite shape

gas

a form of matter that does not have a definite volume or a definite shape

plasma

a collection of charged particles that shows some characteristics of a gas but that differs from a gas in being a good conductor of electricity and in being affected by a magnetic field

chemical property

a property of matter that describes a substance’s ability to participate in chemical reactions

chemical change

a change that occurs when one or two substances change into entirely new substances with different properties

chemical reaction

the process by which one or more substances change to produce one or more different substances

reactant

a substance or molecule that participates in a chemical reacture

product

a substance that forms in a chemical reaction

mixture

A combination of two or more substances that are not chemically combined

homogenous

Describes something that has a uniform structure or composition throughout

solution

a homogenous mixture of two or more substances uniformly dispersed throughout a single phase

heterogenous

composed of dissimilar components

pure substance

a sample of matter, either a single element or a single compound, that has definite chemical and physical properties

group

a vertical column of elements in the periodic table; elements in a _ share chemical properties

family

a vertical column of the periodic table (synonym: group)

period

in chemistry, a horizontal row of elements in the periodic table

metal

an element that is shiny and that conducts heat and electricity well

nonmetal

an element that conducts heat and electricity poorly and that does not form positive ions in an electrolytic solution

metalloid

an element that has properties of both elements and nonmetals; sometimes referred to as a semiconductor