*
Honors Chemistry
*
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Fwww.docstoc.com%2Fdocs%2F2197377%2FHistory-of-the-Atom-Timeline&ei=Lj0eUrToIdbBsATcYCoBQ&psig=AFQjCNGiHQcb3bnDY0VcwwwaBXbg6JrjvQ&ust=1377799854621767
* Element symbols: Always a capital letter or capital letter followed by
lowercase
* Vertical columns are called groups or families.
* Horizontal rows are called periods.
* Metals are on the left of the staircase line; nonmetals are on the right side.
* ******EXCEPT: Hydrogen
* Metals: good conductors of heat & electricity; malleable; ductile; lustrous;
most are strong; lose e- when bonding
* Nonmetals: poor conductors; many are gases; some are brittle solids; gain
e- when bonding
* Metalloids: on the staircase (B, Si, Ge, As, Sb, Te, Po, At); semiconductors
*
The Atom:
Location
Charge
Relative
Size
Proton
Nucleus
+
1
Neutron
Nucleus
0
1
Electron
Electron
Cloud
-
1/1840
* Atomic Symbols:
* p+: proton
* n°: neutron
* A: mass #
* Z: atomic #
* e-:electron
*
*Atoms are the smallest piece of matter that
can be used to identify a substance.
*Each element has a unique number of protons
in each atom.
*Identifying atoms using your periodic table:
http://www.google.com/url?s
a=i&source=images&cd=&cad=
rja&docid=tLbh1gpsmVnHVM&
tbnid=kOfClErZUPVJXM:&ved=
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econdQuarter%2FChapter04%2
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4DICw&psig=AFQjCNE_gCUdC8
WrVOBETQ3npmzwVSV4A&ust=1377868796389213
*
http://www.google.com/url?sa=i&source=images&cd=&cad=rja&docid=YIwAgmlLK4wjyM&tbnid=ddJ3bhUwLYg7BM:&ved=0CAcQjB0wAA&url=http%3A%2F%2Fwww.chem4ki
ds.com%2Ffiles%2Felements%2F006_shells.html&ei=DkofUubKEPPRsASP9YDIBw&psig=AFQjCNGHroYAWr6RABYcBz_HQZetsLkuIA&ust=1377868686334966
* Atoms of the same element do NOT always have the same
number of neutrons in the nucleus.
* The mass number is the total number of protons and neutrons
in the nucleus.
* When atoms are identical EXCEPT for the number of neutrons,
they are called isotopes of the same element.
* The atomic mass printed on the periodic table is the average
mass of the different isotopes. Its units are atomic mass units
(amu).
*
Nuclear Symbol
https://www.google.com/imgres?imgurl&imgrefurl=http%3A%2F%2Fwww.m2c3.com
%2Fchemistry%2FVLI%2FM1_Topic2%2FM1_Topic2_print.html&h=0&w=0&sz=1&tbnid
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*
http://www.google.com/imgres?sa=X&biw=1366&bih=643&tbm=isch&tbnid=sO9osPgr_kvfPM:&imgrefurl=
http://chemwiki.ucdavis.edu/Physical_Chemistry/Atomic_Theory/Atomic_Mass&docid=g6zq01l9iti72M&i
mgurl=http://chemwiki.ucdavis.edu/%2540api/deki/files/4829/%253DIsotope_Notation.png&w=500&h=3
00&ei=u00fUq7ALoWusQSD74DwAQ&zoom=1&ved=1t:3588,r:7,s:0,i:102&iact=rc&page=1&tbnh=174&tbnw
=281&start=0&ndsp=15&tx=164&ty=68
Hyphen notation Oxygen-17
O-17
*
*
* 1. Neon-20 has a mass of 19.992 amu and Neon-22 has a mass of
21.991 amu. In an average sample of Neon atoms, 90% will be
Neon-20 and only 10% will be Neon-22. Calculate the average
atomic mass of Neon.
* 2. 76% of Chlorine atoms are Cl-35 which has a mass of 34.969
amu. 24% of Chlorine are Cl-37 which has a mass of 36.966 amu.
What is the average atomic mass of chlorine?
*Henri Becquerel wrapped uranium salt with
photographic film and placed in the sun…white
spot left on film;
However, it worked again without being
exposed to sun light. The uranium must be
releasing energy.
*Marie Curie continued Becquerel’s work. She
discovered other elements that also release
this energy…called
it “radioactivity”.
*Also discovered radium and polonium.
*
* Properties of Radioactive Elements:
* 1. Alters photographic film
* 2. Makes some compounds fluoresce (glow)
* 3. Produces electric charge
* 4. Damages living cells
*
* 3 Main Types of Decay:
* 1. Alpha (α): releases a 4/2 He nucleus; look like helium, can
burn skin but can be blocked by a sheet of paper
* 2. Beta (β): releases an electron; neutron inside the nucleus
breaks apart and releases an electron (leaving a proton
behind); 100x stronger than alpha blocked by metal
* 3. Gamma (γ): releases energy waves; very high energy
electromagnetic waves; most dangerous; can be blocked by
thick concrete or thick lead
*
http://www.google.com/imgres?sa=G&biw=1366&bih=643&tbm=isch&tbnid=FNPpLfPrpWmqfM:&imgrefurl=http://www.world-nuclear.org/info/NuclearFuel-Cycle/Nuclear-Wastes/Waste-Management-Overview/&docid=McDjZUXr0lJEHM&imgurl=http://www.worldnuclear.org/uploadedImages/org/info/Nuclear_Fuel_Cycle/Nuclear_Wastes/wast3.gif&w=379&h=168&ei=i5UgUoD0HYnKsATcvoH4Dw&zoom=1&ved=1t:3
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*
* 8.
* 9.
* 10.
* 11.
*
* Transmutation: when one element turns into another
* Two ways it can occur:
* 1. Radioactive decay (natural)
* 2. particles bombard a nucleus (laboratory)
* Allows chemists to produce elements that don’t naturally occur (all
elements > #92 are synthetic, and some isotopes of other elements)
* Mass Defect:
* The difference between adding up the particle masses and the total
mass of the actual atom
* If you add the masses of helium’s particles, one atom should weigh
4.033 amu, but it only weighs 4.022 amu. What happened to the missing
mass?
* This was explained by Albert Einstein
*
atoms to decay in a radioactive
sample.
* Can be used to date the remains of
plants and animals.
* After each half life, half of the atoms
have decayed into smaller elements.
http://www.google.com/url?sa=i&source=images&cd=&cad=rja&docid=TZdfsIhgEzaIcM&tbnid=XjzltumkvjvtFM
:&ved=0CAcQjB0wAA&url=http%3A%2F%2Fwww.world-nuclear.org%2Finfo%2FSafety-and-Security%2FRadiationand-Health%2FRadiation-and-Life%2F&ei=Un4oUva8GJPG9gSD3oHQCQ&psig=AFQjCNGiOz8gGf_ZKXA_X9z4h7USIQ0hw&ust=1378471890460194
https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=image
s&cd=&cad=rja&docid=yoILpWiCwzdDM&tbnid=Mc4M6TxMF1UXPM:&ved=0CAQQjB0&url=http
%3A%2F%2Fwww.joeruff.com%2Fartruff%2Fphysics%2FStudent_Page
s%2FThe_Atom%2FNuclear%2520Decay.htm&ei=J38oUsiGGo6a9QS2n
oGIBA&bvm=bv.51773540,d.eWU&psig=AFQjCNHZ6bjL4VkxdpXGire
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* The time required for half of the
*
* 12.If Polonium-32 has a half life of 14.3 days and you start
with 4.0 mg, how many mg will you have after 57.2 days?
* 13.The half life of radon-222 is 3 days. If you wait 15 days
and find 50 grams of radon-222, how much was in the starting
sample?
*
*Splitting of a nucleus into smaller fragments
*When nucleus splits it releases energy (nuclear power)
*High nuclear waste
*Atomic bomb (U, Pu)
*When nucleus splits, it releases neutrons that crash into
other atoms causing them to split… “chain reaction”
*
http://www.google.com/url?sa=i&source=images&cd=&cad=rja&docid=Lz
ugVAmPNfCyEM&tbnid=H04mChcEyAvnSM:&ved=0CAcQjB0wAA&url=http%3
A%2F%2Flibrary.thinkquest.org%2F3471%2Fabomb.html&ei=Q0EeUvydAuK0
sAT4loGoBw&psig=AFQjCNHVttvous4jVsp_aSvuyO5vuDee2w&ust=13778008
99097039
* Combining nuclei to produce larger atoms
* Produces more energy than fission
* Requires very hot temps
* Occurs on the sun and stars
* Low waste
* H bomb (H fusing He)
*
*
https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=im
ages&cd=&cad=rja&docid=l8vXaJS4H6PKuM&tbnid=EtdykNacTW
_6tM:&ved=0CAQQjB0&url=http%3A%2F%2Fwww.atomicarchive.
com%2FFusion%2FFusion1.shtml&ei=_UEeUqusL5O88wSi9oHQDg
&psig=AFQjCNGTP20KLqwni4-LmgDQrntLKA7iw&ust=1377801024997787
*Different elements release waves of energy with
different wavelengths when their electrons are excited
*Electromagnetic waves (also called radiation) can
travel through empty space and travel through some
matter
*All of these waves travel with a velocity of 3x108 m/s
through empty space
*Wavelength v. Frequency: inversely proportional (when
one goes up, the other goes down)
*Frequency v. Energy: directly proportional (when goes
up, the other goes up)
*
*
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ages&cd=&cad=rja&docid=dNeokQHrafq1VM&tbnid=yYWwmoFv
0tUrpM:&ved=0CAQQjB0&url=http%3A%2F%2Fwww.lbl.gov%2FMi
croWorlds%2FALSTool%2FEMSpec%2FEMSpec2.html&ei=UgYtUsGf
OZO9gSJ8IGwDg&bvm=bv.51773540,d.eWU&psig=AFQjCNHgMK4dRqZh5-tyf7JVuwau3WrxQ&ust=1378768379142251
*
* 1. What type of wave has a wavelength of 5 X 103m?
* 2. If a light wave has a wavelength of 5.3 x 10-7m, what color is
it?
* 3. An electromagnetic wave travelling through space has a
frequency of 7.5 X 1020 hz. What is its wavelength? What kind of
wave is it?
* 4. Which waves carry more energy, red light waves or violet light
waves? Explain!
*
*Some evidence suggests that light travels in
clumps of particles called photons instead
of continuous waves.
*The German scientist Max Planck studied
photons and said that atoms of different
elements have different amounts of energy
that can be lost or gained.
*He called this minimum amount of energy
the Quantum energy.
*
*Einstein believed that light has properties
of BOTH waves and particles
*He called this Wave Particle Duality
*This means that photons of light travel in
“packets” called quanta and move up and
down like a wave as they travel from one
location to another
*Electrons act as waves as well as particles
*Energy acts as particles as well as waves
*
* Electrons are released from matter when it is hit by
electromagnetic waves
*
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pro%2Fexperiments%2Fphotoelectric-effect%2F&ei=1gstUpbAHIaA9gTRgoCoBA&bvm=bv.51773540,d.eWU&psig=AFQjCNG7HanVbQg8lkRhoYih1zJ92UKIzg&ust=1378770196315156
*
*As atoms absorb energy, electrons move
into higher energy levels
*When the electrons return to lower energy
levels, the release energy in the form of
visible light
*No two elements release the exact same
spectrum of light waves
*Elements can be identified by the colors of
light they release when electrons jump back
to the lower energy levels
*
*Neils Bohr explained that electrons circle
the nucleus in specific orbits.
*The lowest possible energy level of an
electron is called its ground state(This is
the normal location of the electron.)
*If an electron absorbs energy, it moves up
an energy level absorption
*If an electron gives off energy, it moves
down an energy level (emission).
*