Ch. 1—Chemistry: An Introduction
What is chemistry?
• Chemistry is the study of the ___________________
composition
of substances and the changes they undergo.
alchemy
• It began from “_______________”...
the attempts of alchemists to
change common metals into _________
through trial and error.
gold
Divisions of Chemistry
There are several divisions or branches of chemistry:
1) _________
Organic chemistry: the study of substances that contain ________
carbon
Example: how gasoline is produced from oil
Inorganic
without
2) _______________
chemistry: the study of substances __________
___________
carbon
Example: how table salt reacts with different acids
Divisions of Chemistry (continued)
3) _______________
Analytical
chemistry: the study of the _______________
quantitative
composition of substances
Example: how much chlorine is in a sample of tap water
Biochemistry
living
4) ____________________:
the study of the chemistry of _________
__________________
organisms
Example: how sugar in the blood stream of cats affect
insulin production
Chemistry and Biology
Chemistry and Biology
Chemistry and Biology
Chemistry and Biology
Chemistry and Biology
Chemistry and Biology
Chemistry and Biology
The Scientific Method
•
The scientific method is way to solve a scientific problem. It is an
approach to a solution (using mostly common sense.)
Example: Your flashlight doesn’t work. (Not necessarily a
“scientific problem.”)
Steps to the Scientific Method
observations
(1) Make _________________-Use your 5 senses to gather
information.
hypothesis
(2) Propose a ______________-Make an “educated guess” for what
is happening.
experiments
(3) Perform _______________-This tests your hypothesis. Many
experiments are sometimes needed to test a hypothesis. The same
experiment must give similar results if the experiment is to be
reliable.
Steps to the Scientific Method (continued)
(4) Make a _____________-theory
This should explain the results of your
experiments. Theories may ___________
or be ___________
change
rejected
over time because of results from new experiments.
Scientific Laws
•
•
•
Laws describe ____________
natural
___________________.
phenomena
why the
A law tells what happens. It does not attempt to explain _____
phenomena occurs. (That is the job of a theory.)
math
equation
Laws can often be summarized by a _____________
__________.
Ideal
Gas ______”)
Law
Example: PV = nRT (The “_________
______
This equation is used in Ch. 12. The law shows the
relationship between the pressure, volume and
temperature of a given quantity of gas in a
container.
Chapter 2--Matter & Change
Matter vs. Mass
•
mass and takes up ___________.
space
Matter is anything that has _________
solids __________,
liquids and ________...
gases
Examples: ________,
(the three
phases of matter)
•
•
•
light
Things that are NOT matter: __________,
heat, emotions
________, sound...
Mass is the amount of ___________
in an object.
matter
The standard metric unit for mass is the ______________.
kilogram
States of Matter
phase
fixed shape
fixed volume
compressible
solid
YES
YES
NO
liquid
NO
NO
YES
NO
NO
YES
gas
Particle Motion
•
•
•
•
vibrate
Solids-- particles ____________
back and forth in fixed positions
slide past each other in the container
Liquids-- clumps of particles ______
fly all over the place and collide
Gases-- individual particles _____
_________
Vapor is a term used for a gaseous substance that is normally a
________
solid or _______
liquid at room temperature.)
Example: _______
water vapor
States of Matter
Plasma
•
•
Plasma is a high energy electrically charged mixture of ions and
electrons. __________
are made of plasma.
Stars
While plasma is the most abundant phase of matter in the universe,
on earth it only occurs in a few limited places:
– Lightning bolts
– Flames
– Fluorescent lights
– Aurora Borealis (Northern Lights)
•
•
•
Bose-Einstein Condensate
Predicted in 1924 and created in 1995, the BEC is a small group of
atoms clumped together when taken down to a few billionths of a
degree above absolute zero.
This group of atoms takes up the same place, creating a "super
atom." There are no longer thousands of separate atoms.
They all take on the same qualities and for our purposes become one
blob.
Einstein
Bose
http://www.colorado.edu/physics/2000/bec/
400 nanoKelvins
200 nK
50 nK
Physical Properties and Physical Changes
•
Physical properties can be determined/measured without changing
the substance’s composition.
Examples: _______,
color odor, __________,
taste
mass, ________,
density
_________
point, hardness,
boiling point, ____________
melting
solubility, etc.
•
Physical Changes alter a substance without changing its
composition.
Examples: crushing, ripping, breaking, and any _________
phase
changes…(boiling, freezing, melting, etc.)
•
Most physical changes just alter the size of the particles and are
usually reversible.
Physical Properties
Physical Changes: Names of the Phase Changes
Solid
Gas
Liquid
SolidAqueous = ___________
dissolving
Aqueous  Solid = ___________
crystallizing
•
Mixtures
Mixtures are a physical blend of two or more substances mixed
together.” The parts can be separated by _____________
means or
physical
____________
changes.
physical
There are 2 types of mixtures:
(1) _________________
Heterogeneous Mixtures: the parts mixed together can still be
distinguished from one another...NOT uniform in composition.
Examples: chicken soup, fruit salad, _____,
dirt sand in water
Homogeneous
(2) _________________
Mixtures: the parts mixed together cannot be
distinguished from one another...completely uniform in
composition.
Examples: ______,
Air Kool-aid, ________,
Brass salt water, milk
•
solution
Another term for a homogeneous mixture is a “______________.”
Heterogeneous Mixtures
Homogeneous Mixtures
•
Distillation
One way to separate a _________
solid from a ___________
liquid
in a
solution is by distillation. There are 2 steps to the process:
Step 1: _________
Boil the solution.
Condense
Step 2: ________________
the vapor as is escapes and collect it.
Distillation Animation
•
Chemical Properties and Chemical Changes
Chemical properties cannot be determined/measured without
changing the substance’s composition
Examples: ____________,
burning
whether or not it reacts with an
acid or a base.
Chemical Changes
•
Chemical changes will alter a substance and change its composition.
rusting
Examples: burning, ___________,
rotting or decomposing,
fermenting
__________________,
and other chemical
reactions.
•
Most, but not all, chemical changes are irreversible.
– You can’t “reverse” the burning of paper.
– _____________
use a reversible chemical reaction
Rechargeable ____________
batteries
Indications of Chemical Reactions
1) ________
Heat is produced: (________)
matches
Light is produced: (_____________
lightning
fireflies
2) ________
bugs/_____________)
Electricity
3) ______________
is produced:
(______________)
batteries
Indications of Chemical Reactions
4) ___________________
Precipitate
forms: (_______
soap ________)
scum
Two liquids chemically
react to form a solid.
5) gas/smoke/odor/bubbles produced:
soda
fizz
(________
______)
•
•
Elements vs. Compounds
An element cannot be ___________
broken
down or _____________
changed
into
simpler substances by chemical means.
Elements are the _________
simplest forms of matter that can exists in
normal laboratory conditions.
Examples: _______,
Gold Helium, __________
Mercury
•
•
2 or ________
more different elements
A compound is made up of ____
______________
chemically bonded together.
Compounds can only be broken down into simpler substances by
____________
chemical ____________.
reactions
Water Sand, _______________
NaCl (table salt)
Examples: _______,
Classification of Matter
Classification of Matter
Classification of Matter
•
•
•
Chemical Symbols
Chemists use chemical symbols for the elements involved in a
chemical reaction. The symbols are a shorthand way of representing
the ______________.
(See the Periodic Table for a list of all the
elements
symbols.)
The first letter of the chemical symbol for an element is always
capitalized
_________________.
The next letter, if needed, is _______________.
Each capital letter
lowercase
in a formula, therefore, represents another element.
H ____,
Ne Hg, ___,
S NaBr, ________,
H2O LiC2H3O2
Examples: ____,
•
Some symbols come from _______
Latin names: Au=Aurum (Gold)
•
•
Chemical Reactions
When writing chemical reactions, the substances that ___________
react
with each other are written on the _______
left and are called
“reactants”.
The substances that are ____________
produced are written on the _______
right
and are called the “products.”
Reactants  Products
•
The “ ” symbol can be read as “_______”
yields or “reacts to produce.”
Example:
2H2 + O2  2H2O
two hydrogen molecules plus one oxygen
which means “____________________________________
molecule yields two water molecules
________________________________________________.”
•
•
•
•
Conservation of Mass
During chemical (or physical) reactions, mass (or matter) is neither
_____________
nor _________________.
created
destroyed
The mass of all the reactants _________
equals the mass of all the products.
number of each kind of atom is the same.
The ___________
Sometimes it appears that the reactant and product masses are not
gas was probably a reactant or product in the
equal, but a _______
reaction, and that is making the difference!
Example:
•
•
2H2 + O2  2H2O
If 4 grams of hydrogen reacted with oxygen to produce 36 grams of
32
water, how many grams of oxygen were used? _______
# of H’s and O’s on each side is __________!
constant
Notice that the ____
Conservation of Mass
CaCl2 + Na2SO4  CaSO4 + 2NaCl
mass before = mass after
# atoms before = # atoms after