Exam 1 Ch.1-2
Solution
A homogenous mixture
Chemical reaction
A process whereby substances described as reactants are transformed into different substances called products
Compound
A pure substance that is made up of two or more different types of atoms in a fixed, characteristic chemical combination
Chemical equation
A representation of a chemical reaction using chemical formulas
Green chemistry
A set of key ideas to guide all in the chemical community; calls for designing chemical products and processes that reduce or eliminate the use or generation of hazardous substances
Chemical formula
A symbolize way to represent the elementary composition of a substance
Complete combustion
All of the fuel burns given ample supply of oxygen
VOCs Volatile organic compounds
Carbon-containing compounds that pass easily into the vapor phase
Pure substance
Composed of a single substance
Element
Composed of many atoms of the same type
Hydrocarbons
Compounds composed entirely of hydrogen and carbon atoms
Molecular compounds
Compounds composed of two or more nonmetals
Ionic compound
Consists of positive and negative ions, not molecules
Nonmetals
Elements that may be in gaseous, liquid, or solid states at room temperature. Characterized by poor conductivity of heat or electricity, and those in the slid state cannot be deformed without cracking or breaking
Semiconductors
Intermediate between metals and insulators in their transport of electrons
Stratosphere
Layer above the trophsphere
U.S. Clean Air Act 1970
Led to the establishment of air quality standards
Heterogenous mixture
Not uniform in composition throughout
Secondary pollutant
Produced from chemical reactions involving one or more other pollutants
Combustion
The chemical process of burning; the rapid reaction of fuel with oxygen to release energy in the form of heat and light
Molecule
The combination of more than one atom in a specific spatial arrangement, may only feature a single type of atom
Allotropes
The different ways that atoms are arranged to form the bulk, macroscopic elements
Current electricity
The flow of electrons from one location to another
Toxicity
The intrinsic health hazard of a substance
Nanotechnology
The manipulation of matter with at least one dimension sized between 1-100 nanometers, where 1 nanometer (nm) = 1x10-9m
Risk assessment
The process of evaluating scientific data and making predictions in an organized manner about the probabilities of an outcome
Groups
Vertical columns on the periodic table
Respiration
We take in oxygen in order to help metabolize the foods we eat
Tragedy of the commons
When 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 who use it
Incomplete combustion
With less oxygen, the fuel burns incompletely
Troposphere
lowest layer of the atmosphere, 75% of the mass of the entire atmosphere
Mass number
the number of protons and neutrons residing in the nucleus
Catalyst
A chemical substance that participates in a chemical reaction and influences its rate, without itself undergoing permanent change
Conductive
A material enables the flow of electricty
Insulating
A material that does not allow electricity to flow through
Organic compound
Always contains carbon, almost always hydrogen, and may contain other elements such as oxygen and nitrogen
Matter
Anything that has mass and takes up space; consists of solids, liquids, gases, or plasmas; either pure substances or mixtures
Dmitri Mendeleev
Developed the periodic table
Static electricity
Electricity that builds up in place
Metals
Elements solid at room temperature, shiny in appearance, may be permanently deformed without breaking or cracking, and are conductors of electricity and heat
Metalloids
Elements that lie between metals and nonmetals in the period table, and whose properties do not fall cleanly into either category. Intermediate electrical conductivity
The Pollution Prevention Act 1990
Focused on preventing the formation of hazardous substances
Rocks
Heterogenous mixtures of solid compounds known as minerals
Law of Conservation of Matter and Mass
In a chemical reaction, the mass of the reactants consumed equals the mass of the products formed
Thermosphere
Layer above the mesosphere
Mesosphere
Layer above the stratosphere
Oxygen
Less abundant than nitrogen, about 21% of what we breathe, most abundant element in the human body
Sustainability
Making decisions with a concern not only for today's outcomes, but also for the needs of future generations
Nitrogen
Most abundant substance in the air, constitutes about 78% of what we breathe
Chemical symbols
One or two letter abbreviations for the elements
Ambient air
The air surrounding us, usually meaning outside air
Exposure
The amount of the substance encountered
Exosphere
The last layer of the atmosphere
Composition
The makeup of something
Homogenous mixture
The mixing together of separate pure substances
Mixture
The physical interaction of two or more pure substances present in variable amounts
Atomic number
the number of protons in the nucleus
Atoms
the smallest building blocks of matter
