Transcript An Introduction to Matter

Group Tasks
• Right Side:
• I have developed a way to
make bottled water that I
guarantee will be chemical
free.
• Typically already, bottled
water costs about $3/gallon.
• You need to determine how
much I should charge for
Dr. Joe’s Chemical Free
Water.
• Left Side:
• Recently, a disturbing report
was issued on the dangers of
dihydrogen monoxide. The
biggest concern in the report
was that this chemical had
been detected in a number of
areas (like the air we breathe and
different places in our homes).
• You need to determine what
you would do to protect
yourself from this chemical.
(http://www.dhmo.org)
http://www.dhmo.org
What’s the deal?
• In the first case, we’re assuming water is not a
chemical.
• In the second case, we’re being told it is a
dangerous chemical.
• I ask you then, what is a chemical?
chemicals “bad” or harmful?
• Many people assume chemicals are bad
Are all
What is Chemistry?
• Study of matter and its changes.
• Matter is anything that takes up space and
has mass.
• WOAH!! Isn’t that nearly everything?
• So chemistry plays a role in your everyday
life, more than you probably know!
Balloons
• Why the differences?
• Because it’s different stuff in there, right?
• Yes, but, that’s not enough of an answer in
science! We want to know why those
particular “things or chemicals” did those
different things.
Macroscopic vs Nanoscale
• What we saw happen we say occurred on a
macroscopic level
• To really understand why it happened, we need to
look at a level we can’t see with our naked
eyes…a microscopic level
• Actually, we need to look at the behavior of atoms
and molecules…this is called the nanoscale level
• Much of what we’ll do in here is attempt to
explain what we see at a macroscopic level in
terms of the nanoscale!!!
Properties of Matter
• Physical
–
–
–
–
During a physical change,
the fundamental particles
are not changed
Color
Mass
Volume
State (solid, liquid, gas)
•Chemical
During a chemical change,
–it reacts with acid the fundamental particles
–it does not react
are changed
with air
Density
• Amount of mass filling a volume
• Density = mass/volume
• Constant for a material (at a given
Temp)
Using Density
• At a certain temperature, ethanol has a density of
0.80 g/mL. If I needed 150 g of ethanol, what
volume of ethanol would I need to measure out?
1 mL
150 g
= 187.5 mL
0.80 g
Dalton’s Atomic Theory
1. All matter is composed of indivisible atoms.
2. An element is a type of matter composed of only 1 type
of atom.
3. A compound is a type of matter composed of atoms of
two or more elements chemically combined in fixed
proportions.
4. A chemical reaction is simply a rearrangement of the
atoms present to give new chemical combinations.
– A physical change is a change that does not
alter the identity of the matter.
– A chemical change is a change that does alter
the identity of the matter.
– A compound is a pure substance that can be
decomposed by a chemical change into simpler
substances
– An element is a pure substance which cannot
be broken down into anything simpler by either
physical or chemical means.
• Chemical Change: Sugar is a compound that can be
easily decomposed to simpler substances by heating.
One of the simpler substances is the black element
carbon, which cannot be further decomposed by
chemical or physical means.
Ice
Water
Steam
• Physical Change: (H2O) As a solid, liquid, or gas still has
only H2O water molecules present. The “H” and “O” are
not broken apart going from ice, water, to steam. Only the
energy per individual H2O molecules changes.
Atom
Identifying an Atom
• Atoms of a particular element will all
have same number of protons
• Z = atomic number
• A = atomic mass number
• Write Nuclide Symbols to Identify
Atom
A
Z
Symbol
Nuclide Symbols
• Write the nuclide symbol for an atom
with mass number 15 and 8 neutrons.
An atom that has the same number of
neutrons as 59
is
27 Co
59
28
Ni
57
27
Co
60
29
Cu
58
26
Fe
Atomic Mass
1 Atomic Mass Unit = A.M.U. = amu
1 amu = mass of the proton = mass of the neutron
The Periodic Chart lists atomic mass underneath the
atomic symbol
The Mole
number of atoms needed to have
atomic mass in grams
6.02 x 1023
Using the Mole
• The link between macroscopic grams
and nanoscale number of particles!
• If I had 0.750 mol of Pb,
– How many grams of Pb must I have?
– How many atoms of Pb must I have?
The Periodic Table
“Periodic Trends”
The Real Periodic Table
The Periodic Table
• Rows are periods
• Columns are groups
• “sections”
Main Group
Metals
Transition
Nonmetals
Inner Transition
Metalloids