Chemistry Ch. 1: The Air We Breathe
Percent (%)
Parts per 100
Megacities
Urban areas with 10 million people or more
Volatile Organic Compounds(VOCs)
carbon containing compounds that pass easily into vapor phase
Nanotechnology
the creation of materials at the atomic and molecular (nanometer) scale
Groups
Elements fall into vertical columns which organize elements according to important properties that they have in common and are numbered from left to right
Periodic Table
Most common way of arranging the elements
Chemical Symbols
One- or two-letter abbreviations for the elements
Toxicity
The intrinsic health hazard of a substance
Troposhere
The lower region pf the atmosphere in which we live that lies directly above the surface of the Earth. Contains the air currents and turbulent storms that turn and mix our air.
Catalyst
a chemical substance that participates in chemical reaction and influences its rate without itself undergoing permanent change
Compund
a pure substance made up of two or more different elements in a fixed, characteristic chemical combination
Green Chemistry
a set of key ideas to guide all in the chemical community
Chemical formula
a symbolic way to represent the elementary composition of a substance
Organic Compound
always contain carbon, almost always contains hydrogen, may contain other elements like oxygen and nitrogen
Hydrocarbons
compounds made up only of the elements carbon and hydrogen
Metals
elements that are shiny and conduct electricity and heat well
Nonmetals
elements that do not conduct heat or electricity well and have no one characteristic appearance
Metalloids
elements that lied between metals and nonmetals on the periodic table and do not fall cleanly into either category
Sustainability
meeting the needs of the present without compromising the ability of future generations to meet their own needs
Diatomic substance
molecule consisting of two atoms
Element
one of the 100 or so pure substances in our world from which compounds are formed
Mixture
physical combination of two or more pure substances present in variable amounts.
Chemical reaction
process whereby substances described as reactants are transformed into different substances called products
Ambient Air
refers to the amount of air surrounding us
Chemical equation
representation of a chemical reaction using formulas
Volatile
substance readily passes into vapor phase
Exposure
the amount of the substance encountered
Combustion
the chemical process of burning, rapid reaction of fuel with oxygen to release energy in form of light and heat
Respiration
the foods we eat are metabolized to produce carbon dioxide and water.
Shifting Baselines
the idea that what people expect as "normal" on our planet has changed over time, especially with regard to ecosystems
Atoms
the smallest unit of an element that can exist as a stable, independent entity
Molecule
two or more atoms held together by chemical bonds in a certain spatial arrangement
