Chemistry in Context: Chapter 2

catalyst

a chemical substance that participates in a chemical reaction and influences its rate, without itself undergoing permanent change

organic compound

a compound that always contains carbon, almost always contains hydrogen, and may contain other elements such as oxygen and nitrogen

law of conservation of matter and mass

a law stating that in a chemical reaction, matter and mass are conserved

mixture

a physical combination of two or more pure substances present in variable amounts

secondary pollutant

a pollutant produced from chemical reactions involving one or more other pollutants

chemical reaction

a process whereby substances described as reactants are transformed into different substances called products

chemical equation

a representation of a chemical reaction using chemical formulas

nitrogen oxides

can form naturally in grain silos and can injure or kill farmers who inhale it di: characteristic brown color and is the primary visible component of urban smog; can also combine with moist tissue in your lungs to form an acid mono: another colorless pollutant

carcinogenic

capable of causing cancer

particulate matter

complex mixture of tiny solid particles and microscopic liquid droplets; least understood of the air pollutants; classified by size instead of composition

sustainability

meeting the needs of the present without compromising the ability of future generations to meet their own needs

hydrocarbon

organic compounds comprised entirely of carbon and hydrogen

percent

parts per hundred. For example, 15% is 15 parts out of 100

ozone

sharp odor; harmful pollutant that reduces your lung function and mottles the leaves of crops and yellows pine needles

sulfur dioxide

sharp unpleasant odor; it dissolves in the moist tissue of your lungs to form an acid

carbon monoxide

silent killer; no color, taste, or smell; interferes with the ability of your hemoglobin to carry oxygen

ambient air

the air surrounding us, usually meaning the outside air

exposure

the amount of a substance encountered

combustion

the chemical process of burning; the rapid reaction of fuel with oxygen to release energy in the form of heat and light

green chemistry

the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances

toxicity

the intrinsic health hazard of a substance

troposphere

the lowest region of the atmosphere in which we live that lies directly above the surface of Earth

risk assessment

the process of evaluating scientific data and making predictions in an organized manner about the probabilities of an outcome

respiration

the process of metabolizing the foods we eat to produce carbon dioxide and water and to release energy that powers other chemical reactions in our bodies

tragedy of the commons

the situation in which a resource is common to all and used by many, but has no one in particular who is responsible for it. As a result, the resource may be destroyed by overuse to the detriment of all that use it

molecule

two or more atoms held together by chemical bonds in a certain spatial arrangement