ChemistryThe study of the
composition, structure, and properties of matter.
Chemistry also studies the changes that matter undergoes.
Fields of ChemistryInorganic Chemistry
The study of chemicals, in general, that do not contain carbon
Organic ChemistryStudy of chemicals containing carbon
Analytical ChemistryComposition of matter
Physical ChemistryInvestigates the mechanism, rate and energy transfer
that occurs when matter undergoes changeBiochemistry
Study of processes that occur within organisms
ChemicalSubstance that is
the same no matter where it is found.More details to
come later.Instruments used in
chemistry, such as x-rays or electron microscopes, are used to identify chemicals.
Chemicals IIWhere are chemicals
found?Everywhere
Toothpaste Hair gel Soap Shaving cream Shoes Clothing Hand sanitizer
Chemical ReactionsChemicals undergo
change.These changes occur
via chemical reactions.Cooking foodStriking a matchCar enginesRunningOpening a soda
bottle
Matter/MassMatter can be defined as
anything that occupies space and contains mass.
Chemical particles help make up matter and mass.
The arrangement of these particles determine certain properties of the matter.These are called
physical properties.
LiquidsHas a fixed volume but
no shapeLiquids assume the
shape of whatever medium they are in.
Particles are not held together very well.The bonds, that hold
the particles together, break apart easily
Vibration of the particles is increased.
GasesHave no fixed
volume and no fixed shape.
Particles are weakly attracted to each other.
Particles move and vibrate at high speeds.
Physical Changes of MatterPhysical changes are changes in which the
identity of a substance does not change.Physical changes are about energy and states of
matter.Example
When one steps on a can, and crushes it, a physical change occurs. The shape of the object has changed
Melting ice cube The shape of the object has changed Energy has been added {heat}
The molecules start to move faster and faster
Causes of Physical ChangesOne can use
different types of force to cause a physical changeMotionTemperaturePressure
Small Physical ChangesMelting a sugar
cubeThe substance is
still sugar Burning a sugar cube
results in a chemical change
Chemical ChangeIn a chemical
change, the identity of the substance changes and a new substance is formed
They happen on a much smaller scale.Molecular level
Chemical Change IISome are changes
are obvious.There is a color
change. When Iron (Fe) rusts
You can see it happen over a long period of time.
Burning of a sugar cube The fire breaks bonds
The sugar cube becomes blackened.
Chemical Change IIIWood Burning in
FireplaceChemical change
When the wood burns, heat is given off, gases leave and a residue of ashes remain.
The wood was changed into several new substances.
How are Chemical Changes Represented?Chemical changes are represented via a
chemical reaction.Sometimes, a series of chemical reactions must
occur.Chemical reactions are represented by a
chemical equationReactants Products
Mercury (II) oxide Mercury + Oxygen
Chemical ReactionsThere are two parts
to a chemical reactionReactions
What the scientist puts in
Products What the scientist
gets out of the process
Evidence of Chemical ChangesThe formation of gasFormation of precipitate
When two clear solutions, when mixed together, become cloudy
The release or absorption of energyChange in temperature
Change in colorNew odor produced