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