Environmental Chemistry Study Guide:
A.1
Quantitative data: quantities that are measured.
Qualitative data: observations that you can observe with your senses.
Inference: a conclusion that you make on a lab.
Density: the mass per unit volume of a given material that is often expressed as g/cm3.
Volume: the amount of space a substance occupies, (measured in cubic units).
A.2 Properties Make the Difference
Physical properties: properties that can be determined without altering the chemical makeup of the
material.
Physical change: the material remains the same, even though its form appears to have changed.
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Melting
Boiling
Bending
Chemical properties: any kind of chemical changes a substance undergoes, often determine its
usefulness. Example (iron rusting)
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Formation of a gas or solid
A permanent color change
A temperature change
A.3 Developing Skills: Physical and Chemical Properties
Definitions found in the section:
Combustion: burning – involves a chemical reaction.
Ductile: can be drawn into wires
Luster: shiny and reflect light
A.4 Properties of Matter: Designing the Penny
Copper was getting expensive.
1943: Zinc-plated pennies: within 1 year corroded
1982: Zinc Core, thin copper outer layer.
A.5 The Particulate View of Matter
Particulate level: at the level of their atoms and molecules
Matter: anything that occupies space and has mass
Atoms: the building blocks of matter.
Element: matter is made up of only one kind of atom called an element.
Compound: a substance composed of atoms of two or more elements linked together chemically in
certain fixed proportions.
Substance: each element and compound having a uniform and definite composition as well as distinct
properties.
Molecule: a collection of atoms that move and act together as a single entity.
Chemical bonds: the “glue” that holds atoms of a molecule together.
A.6 Symbols, Formulas and Equations:
Chemical symbols: letters to represent elements.
Chemical formula: “words” in the language of chemistry – represents a different chemical compound.
Coeeficient: Number in front of a substance. The relative number of units of each substance involved in
the chemical reaction.
Subscript: a small number written below the normal line of letters indicates how many atoms of the
element just to the left of the subscript are in one unit of the compound.
Reactants: the original (starting) substances in a chemical reaction. Their formulas are always written on
the left side of the arrow.
Products: the rearrangement of the reactant atoms. Their formulas are always written on the right side
of the arrow.
A.7 Chemical Symbols and Formulas
You may use your periodic table to find elements and their symbols.
A.8 Modeling Matter – Pictures in the Mind
Macroscopic world: world filled with large-scale (“macro”0) readily observed things.
Models: representation of atoms and molecules.
A.9
Properties of Metals:
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lustrous (shiny)

good conductors of heat and electricity

high melting point

high density (heavy for their size)

malleable (can be hammered)

ductile (can be drawn into wires)

usually solid at room temperature (an exception is mercury)

opaque as a thin sheet (can't see through metals)


metals are sonorous or make a bell-like sound when struck
each metal atom

corrode easily (e.g., damaged by oxidation such as tarnish or rust)

lose electrons easily

form oxides that are basic

have lower electronegativities

are good reducing agents
Nonmetals
Nonmetal Physical Properties
 not lustrous (dull appearance)

poor conductors of heat and electricity

nonductile solids

brittle solids

may be solids, liquids or gases at room temperature

transparent as a thin sheet
nonmetals are not sonorous
Nonmetal Chemical Properties
 usually have 4-8 electrons in their outer shell


readily gain or share valence electrons

form oxides that are acidic

have higher electronegativities

are good oxidizing agents
Nonmetals
Metalloids: have properties that are intermediate to those of metals and nonmetals. Example (Si)
Silicon and (Ge) Germanium.
Conductor: a material where electricity is flowing through.
Non-conductor: a material where electricity fails to flow through.