Presented by
V.J. Eddy-Helenek
September 2016
Chemistry
is the study of the
composition, structure and properties of
Matter,
the changes that matter undergoes, and the
energy accompanying those changes.
“What’s Matter?”
“Everything!”
Categories of Matter
Mixtures
Homogeneous Heterogeneous
Pure Substances
Compounds
Elements
Matter
has mass and takes up space
Mixtures
Contain two or more pure substances
And may be separated by physical methods
Pure substances
(chemicals)
contain only
one kind of particle
Homogeneous mixtures
have the same composition throughout,
i.e. alloys 14Kt gold, homogenized milk
Compounds Contain only one kind of
Heterogeneous mixtures
particle, made up of two or more different
Composition varies from
elements, chemically bonded in a
one part of sample to another
definite ratio,
such as H20, CO2,or NaCl
Elements are the simplest pure substances
contain only one kind of atom,
such as Fe, Ne, or Au
Law of Conservation of Matter
“Matter cannot be created or destroyed, only transformed.”
Reactants Products
Total mass of the reactants = total mass of the products!
Chemistry Reference Tables
Safety Contracts due by Friday
Materials: notebook, non-graphing
scientific calculator,
Lab Safety Instructions: hair,
footwear, safety googles, glassware
Add acid
Ask
Magnesium ribbon was burned to produce magnesium oxide
according to the following balanced equation
2Mg(s) + O2(g) 2MgO(s)
If 24 g of magnesium reacted with oxygen
to produce 40 g of magnesium oxide, how much oxygen was
consumed?
Have No Fear Of Ice Cold Beer
H2
Cl2
O2
N2
F2
I2
Br2
These elements exist naturally as diatomic molecules
The phase and physical properties of
matter depend upon the conditions of
temperature and pressure
Under Standard Conditions, most elements are solids
Only mercury (Hg) and bromine (Br2) exist as liquids at STP
N2, O2, F2,Cl2 He, Ne, Ar, Kr, Xe, Rn exist as gases at STP
25C or 298 K for
liquids and solids
0C or 273 K for gases
1 atmosphere pressure
(1 atm = 760 torr or 760 mm Hg or 101.3 kPa)
“It followed from the special theory of relativity
that mass and energy are both but different
manifestations of the same thing -- a
somewhat unfamiliar conception for the
average mind. Furthermore, the equation E is
equal to m c-squared, in which energy is put
equal to mass, multiplied by the square of the
velocity of light, showed that very small
amounts of mass may be converted into a very
large amount of energy and vice versa. The
mass and energy were in fact equivalent,
according to the formula mentioned before.
This was demonstrated by Cockcroft and
Walton in 1932, experimentally."
Einstein’s Theory of Relativity
E=
2
mc
wheeee
!
Burning calories is one way to turn matter into energy!
Elements are made up of atoms, the basic units of matter
A neutron walked into a bar
and asked how much for a drink.
The bartender replied,
"for you, no charge."
-Jaime - Internet Chemistry Jokes
(+)
(-)
Protons have a positive charge
Electrons have a negative charge
Neutrons have no charge
12
C
6
The Atomic symbol is the one or
two letter abbreviation for an
element.
The atomic number is the number of protons in the nucleus of an
element.
The atomic mass is approximately equal to the number of
neutrons plus protons. It is actually the weighted average of the
masses of all of the isotopes of an element, resulting in non-integer
masses.
In a neutral element the number of electrons equals the
number of protons. Electrons are only about 1/1800 as heavy as
neutrons and protons, and do not contribute significally to the
atomic mass.
Isotopes of an element have the same number of protons
(atomic number) in the nucleus, but have different
numbers of neutrons, resulting in different atomic masses.
Hydrogen has
three isotopes.
Each contains
one proton and
one electron.
There can be
none, one or
two neutrons.
The molar mass for elements is the average
atomic mass expressed in grams per mole
.
12.011
C
6
1 mole of Carbon weighs
12.011grams
196.96
Au
79
1 mole of gold weighs
196.96 grams
N = 6.02 x 1023 particles in one mole of matter
12.011
196.96
6
79
C
Au
1 mole of Carbon weighs
12.011grams
1 mole of gold weighs
196.96 grams
1 mole of Carbon contains
1 mole of gold contains
6.02 x 1023 particles
6.02 x 1023 particles
Two Worlds of Chemistry
Sub Microscopic
Conversion
Macroscopic
World
World
number
1 atom
==> x 6.022 E 23 ==>
1 mole of atoms
1 molecule
==> x 6.022 E 23 ==>
1 mole of molecules
mass
1 AMU
==> x 6.022 E 23 ==>
1 gram
1 carbon atom = 12 AMU of
carbon atoms
==> x 6.022 E 23 ==>
1 mole of carbon atoms = 12
grams of carbon atoms
volume
volume of 1 molecule at STP,
3.72 A3
==> x 6.022 E 23 ==>
volume of 1 mole of gas
molecules at STP, 22.4 Liters
1 dozen=12 items, 1 gross=144 items ,1 mole=6.022 x1023 items
H2
1.008
H
1
1 mole of Hydrogen
weighs 2.016 grams
1 mole of Hydrogen contains
6.02 x 1023 Hydrogen molecules,
but 1.20 x 1024 Hydrogen atoms
One mole of hydrogen gas has
a volume of 22.4 liters at STP
F2
18.998
9
F
1 mole of Fluorine
weighs 37.996 grams
1 mole of Fluorine contains
6.02 x 1023 Fluorine molecules,
but 1.20 x 1024 Fluorine atoms
One mole of fluorine gas has a
volume of 22.4 liters at STP
One mole of a gas contains 6.02 X 1023 molecules and
occupies 22.4 liters of space at STP, regardless of the
identity or atomic mass of the gas.
Molarity is a measurement of solution concentration, expressed in
numbers of moles of solute dissolved in 1 Liter of solution.
Units of molarity are moles/Liter, represented by the symbol, M
Three ways to calculate moles of a substance
http://library.thinkquest.org/10429/high/atomic/atomicbody.htm#subatomic
"In light of knowledge attained, the
happy achievement seems almost a
matter of course, and any intelligent
student can grasp it without too much
trouble. But the years of anxious
searching in the dark, with their intense
longing, their alterations of confidence
and exhaustion and the final
emergence into the light -- only those
who have experienced it can
understand it."
There are thousands of websites designed to
make chemistry more understandable and
enjoyable. Surf and learn what everything is
all about….
http://library.thinkquest.org/10584/data/frame/unit02.html
Student Activity: Care to toss some electrons at a nucleus?
Just click here to play atomic physicist!
Bibliography
http://www.pppl.gov/fusion_basics/pics/dt_atoms_sm.gif
http://www.osha-slc.gov/SLTC/silica_advisor/silicosis/silica.gif
http://library.thinkquest.org/3659/atommole/matter.html
http://www.colorado.edu/UCB/AcademicAffairs/ArtsSciences/physi
cs/PhysicsInitiative/Physics2000/waves_particles/wavpart2.html
(play add electron…fun activity for students)
http://library.thinkquest.org/10584/data/frame/unit02.html
http://web.jjay.cuny.edu/~acarpi/NSC/2-matter.htm
This page has good pix of water in solid, liquid gas states of matter
http://web.jjay.cuny.edu/~acarpi/NSC/3-atoms.htm
This page has excellent pix of atoms with nuclei and orbiting
electrons
Bibliography
http://www.uky.edu/Projects/Chemcomics/
http://www.worldsofsearching.org/
http://www.scifair.org/
www.acs.org
www.chemistry.org
www.acdlabs.com
www.can-do.com
http://7-12educators.about.com
www.chem4kids.com
Acknowledgements
Thanks Diane, for your expertise and technical assistance
in helping me to overcome my fear of PowerPoint!