GENERAL CHEMISTRY I: Chapter 1 Essential Ideas

chemistry

the study of composition, properties, and interactions of matter; the study of matter and how it transforms from one form to another

the scientific method

the path of discovery that leads from question and observation to law or hypothesis to theory, combined with experimental verification of the hypothesis and any modification of the theory

hypothesis

a tentative explanation of observations that act as a guide for gathering and checking information; tested by experimentation, calculation and/or comparison

theory

well substantiated, comprehensive, testable explanation of particular aspects of nature; can be modified with new data

the laws of science

summarize a vast number of experimental observations and describe or predict some facet of the natural world

chemoluminescnece

artificial light without heat

bioluminescense

production and emission of light by a living organism

macroscopic domain

realm of everyday things that are large enough to be sense directly with sight or touch

microscopic domain

visited in the imagination; some visible through standard optical microscopes; most objects however are too small to be seen with microscopes

symbolic domain

contains the specialized language used to represent components of the macro and micro domains

matter

anything that has occupies space and has mass

solid

rigid and has a definite shape

liqiuid

flows and takes the shape of its container

gas

takes both the volume and shape of its container

plasma

a gaseous state of matter that contains appreciable number of electrically charged particles

mass

amount of matter in an object

weight

the force of gravity exerted on an object

law of conservation of matter

there is no detectable change in the total quantity of matter present when matter converts from on type to another or changes among liquid, solid, or gas

pure substances

constant composition with the same makeup and properties; divided into elements and compounds

elements

pure substances that can not be broken down into simpler substances

compound

pure substances that are made up of two or more elements chemically bonded; can be broken down by chemical changes

mixture

composed of two or more types of matter that can be present in varying amounts and can be separated by physical chnages

heterogenous mixture

a mixture with a composition that varies from point to point

homogenous mixture (solution)

uniform composition and appears visually same throughout

atom

smallest particle of an element that has properties of that element and can enter into a chemical combination

molecule

consists of two or more atoms joined by strong forces called chemical bonds

physical property

a characteristic that is not associated with a change in its chemical composition; density, color, melting/boiling points, and electrical conductivity

physical change

change in the state or properties of matter without any accompanying change in the chemical identities of the substances contained in the matter— can change back

chemical property

the ability to change from one type of matter into another; flammability, toxicity, acidity

chemical change

produces one or more types of matter that differ from the matter present before the change

extensive property

if the property depends on the amount of matter present; mass volume, heat

intensive property

if the property of a sample does not depend on the amount of matter present; temperature, density

measurements

p

international system of units/ SI units

standards for units are fixed by an international agreement

volume (m³

the measure of the amount of space an object occupies

density

the ratio of the mass of a smap

exact number

a counting measure; free of uncertainty

quantities

derived from measurements other than counting and are uncertain due to its practical limitations of the measurement process used

precise

measurement yields very similar results to when it is repeated in the same manner

accuracy

measurement yields to a result that is very close to the true and accepted value

dimensional analysis

the units of quantities must be subjected to the same mathematical operations as their associated numbers

unit conversion factor

a ratio of two equivalent quantities expressed with different measurement units can be used as a

temperature

refers to the hotness or coldness of a substance