chemistry ch 1 vocab

chemistry

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 an object

atom

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

element

a substance that cannot be separated of broken down into simpler substances by chemical means; all atoms of an element 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 a 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 definitive volume but not a definite shape

gas

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

plasma

in physical science, a state of matter that starts as a gas and then becomes ionized; it consists of free moving ions and electrons, takes on an electric charge, and its properties differ from those of a solid, liquid, or gas

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 more substances change entirely into 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 reaction

group

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

family

a vertical column of the periodic table

period

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 hear and electricity poorly and that does not form positive ions in an electrolytic solution

metalliod

an element that has properties of both metals and nonmetal; sometimes referred to as a semiconductor