Post on 11-Jan-2016
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Qualitative Chemistry
Valence Electrons
The electrons in an atom’s outermost orbit; determine the chemical
properties of an element.
Electron Dot Structure
Consist of the atomic symbol and dots which represent the number of electrons in the out most
energy level of than element
Octet Rule
States that atoms lose, gain, or share electrons in order to
acquire a full set of eight valence electrons.
Oxidation Number
The superscript which tells the charge of the element and the number of electrons it needs or can give up in order to be stable
Anion
A negatively charged ion
Cation
A positively charged ion
Monatomic Ion
An ion formed from only one atom
Polyatomic Ion
An ion made up of two or more atoms bonded together that acts as a single unit with
a net charge.
Coefficient
Is the number found in front of an ion or
compound. It tells the number of that ion or compound you have
Types of chemical bonds
• Ionic Bonds
• Covalent Bonds
• Metallic Bonds
Bonding Pair
Pair of valence electrons which bond two atoms together.
Lone Pair
Pair of valence electrons which are
not bonded to another element.
Unpaired Electron
A valence electron that is not partnered with
another electron.
Double Bond
Where two elements are bonded together
by two pairs of valence electrons. (4 electrons)
Triple Bond
Where two elements are bonded together
by three pairs of valence electrons. (6
electrons)
Physical ReactionWhen a substance
changes physically but the substance stays
the same.
Chemical ReactionWhen a substance
goes through a reaction and changes
into another substance.
Signs of Chemical Change• Change of color
• Release of gas
• Release of energy
• Release of heat
• Absorption of heat
• Release of light
Intensive Property
A physical property that remains the same no matter how much of a substance is present.
Extensive PropertyA physical property, such as mass, length, and volume, that is dependent upon the
amount of substance present.
Qualitative DataInformation describing color, odor, shape, or some other physical
characteristic.
Quantitative DataNumerical information describing how much,
how little, how big, how tall, how fast, etc.
MixtureWhen more than one compound is mixed together to form a substance. The
compounds can physically be separated.
Heterogeneous Mixture
One that does not have a uniform composition and in
which the individual substances remain distinct
Homogeneous Mixture
One that has a uniform composition
throughout and always has a single phase;
also called a solution.
Solute
A substance that is dissolved by another substance. There is
less of it.
Solvent
A substance that dissolves another
substance. There is more of it.
Unsaturated Solution
A solution that is able to dissolve additional
solute.
Saturated Solution
A solution that cannot dissolve any more solute
under the given conditions.
Supersaturated Solution
refers to a solution that contains more of the
dissolved material than could be dissolved by the
solvent under normal circumstances.
Phase Changes
• Solid
• Liquid
• Gas
• Plasma
Solid
The phase where the particles are held very
close together and hold a definite shape.
Liquid
The phase where the particles are held close together and do
not hold a definite shape. Usually takes the shape of the
container.
Gas
The phase where the particles are held near each other and has no
definite shape
Plasma
A state of matter where particles have been reduced to its most basic form. Usually found in stars
As a substance is heated, the particles move more, this causes the substance to expand. When cooled, the substance contracts. The exception to this is water, which expands when cooled and heated.
Ways Matter Change• Melting
• Freezing
• Evaporation
• Vaporization
• Condensation
• Sublimation
• Solid to liquid
• Liquid to solid
• Liquid to gas
• Liquid to gas
• Gas to liquid
• Solid to gas
Melting PointThe exact temperature
at which a solid changes into a liquid
Boiling Point
The exact temperature at which a liquid
changes into a gas
Heating Curve for Water
120 °C
steam 100 °C water steam
50°C liquid water
0 °C ice liquid -10 °C ice Heat added
Viscosity
A fluid’s resistance to flow
Accuracy and Precision
Precision
Is the degree of exactness to which the measurement of a quantity can be reproduced
Accuracy
Is the extent to which a measured value agrees with the standard value of a quantity.
Precision and Accuracy