Language of chemistry- prelim 1

sizes of atom

atoms get smaller from left to right on periodic table smallest atom is Helium, not Hydrogen. increasing number of protons from left to right draws electrons closer to nucleus, making overall atom smaller

dirty bomb

attack from the outside that causes the release of radioactive material

flaws in mendeleev's periodic table

did not know where to put transition metals did not predict existence of noble gases over-predicted number of elements between hydrogen and lithium

William ramsay (1852-1916)

discovered a number of noble gases isolated Helium krypton (hidden) neon (new) xenon (stranger) argon (lazy one) after heating minerals not reactive, group 0, placed between halogens and alkaline metals

fall of 2009

discovered existence of enrichment facility at Qum appeared to be underground facility at Nataanz site

frederick soddy

discovered isotopes- notices that radioactive elements would be emitted different radioactive particles (alpha beta gamma) suggestion of third subatomic particle- neutron isotopes- same number of protons but different number of neutrons

thomas graham

discovered relationship between the rate a gas moves and the molecular mass of the gas. molar mass equation

otto hahn

discovered there was no heavy atom in fermi's sample heaviest atom found was krypton- much lighter than uranium

Irene Joliot

discovery of radioactive nitrogen indirectly discovered neutron

chemical reactivity

doebereiner and chancourtois notice that certain groups of atoms behave similarly. atomic masses display periodicity as you go further out from the nucleus, the easier it is to remove valence electron

US was first to introduce Iran to nuclear power

during 1970s when Shah was in power.

elements

electrons described by 4 quantum numbers atomic number equal to number of protons

nuclear fission

enrico fermi wrongly predicted that if he bombarded uranium atoms it would create a heavier particle with the release of a beta particle.

fissile, stable, fertile nuclides

fissile- decays and is unstable stable- stable and does not decay fertile nuclide- can be prompted to decay

Fermi and the Manhattan project

fled Italy trying to create a self-sustaining nuclear chain reaction required small amount of neutrons to start reaction, but had capacity to produce huge quantities of energy nuclear fallout- release of neutrons, krypton, barium discovers 1st self-sustaining nuclear chain reaction took place on football field Univ. of chicago

Hahn, meitner, fritz

found two isotopes of krypton uranium atom was being split apart- fission uranium 235 atom that can undergo nuclear fission is known as a fissile nucleus unnatural process, unlike radioactive decay which is natural unexplained energy: E=mc^2

Dmitri Mendeleev (1834-1907)

gets most credit for modern periodic table decided to group elements by chemical reactivity left room in periodic table for undiscovered atoms has 8 groups (columns left to right) and periods (rows up and down) elements in same group were chemically similar

shirley turner king

guilty as accomplice of murdering family and burning their house down fingerprints allegedly found on gas canister confirmed years later that her fingerprint lifted friendly's, former place of employment king sent to jail though there was reasonable doubt of the evidence

nuclear weapons

gun-type weapons and compression weapons require enriched U235 or Pl239 90% abundance in nuclear weapon- process to enrich uranium to that level is difficult. need sub-critical/critical mass, amount of U of Pl to have a self-sustaining nuclear reaction

in order to determine whether Iran is developing nuclear weapons

look for uranium enriched beyond a certain point

In agreement Iran makes the following promises

1. will reduce the number of centrifuges from 19,000 to 1,604, with only 5,000 operating at a time 2. Iran limit 3.67% U-235 3. Qom facility only for civilian use w/ no fissile material 4. 7500 kg of LEU reduced to 300 kg (export or dilute) 5. Arak reactor shut down and filled with concrete, and have no new ones to be built 6. full inspections and have them requested 7. inquiry into past activity prior to 2004 8. sanctions relief 9. codified into UN resolutions, signed off by the security council.

pros and cons of nuclear power

-uses less fossil fuel for the production of electricity -is less polluting if you don't consider radioactive waste -radioactive waste difficult to dispose of safely -becomes target for evil doers -potential for accidents

periodic trends

1. atomic radius gets larger from top to bottom and right to left 2. electron affinity (how much an atom wants an electron) increases left to right and bottom to top, with increasing # of protons 3. ionization energy (energy needed to remove an electron) increases left to right and bottom to top 4. electronegativity (tendency to hold onto an electron) increases bottom to top 5. metallic character increases from top right toward bottom left 6. non metallic character increases from bottom left to top right

George bush claimed that iran's production of nuclear power was inconsistent with what they needed because they already

1. have electricity 2. they were fortifying facilities as if to prevent an airstrike 3. leadership in iran was worrysome 4. 2009 public announcement of a secret facility at QOM

John Dalton

1766-1844 England ATOMIC THEORY- elements made up of small particles called atoms all atoms of a given element are identical (Wrong, isotopes) atoms of one element are different than the atoms of another element atoms of one element can combine with atoms of another element to form compounds atoms are indivisible in chemical processes (wrong)

Joseph John (JJ) thompson

1865-1940 applied electric charge to cathode ray tube, noticed beam of light 1st experiment- cathode ray enters apparatus. deflects cathode rays with a magnet and into metal cylinder concluded that the ray and charge were one in the same and could not be separated

generally agreed upon stable numbers- MAGIC numbers of protons

2 8 20 28 50 82 114

stable/MAGIC numbers of neutrons

2 8 20 28 50 82 126 184

issues with Dalton's atomic theory

2. incorrect because discovery of isotopes, not all atoms of a given element are identical

radioactive decay

40 isotopes- radioactive nuclides continuously breaking down (by emitting alpha or beta particles) radioactive decay in Uranium decay series 238/92 U 234/90 Th (+ alpha) 234/91 Pa (+ beta) 234/92 U (+alpha) U 238 ultimately decays to lead-206, a stable isotope Pb

percentage of the world that would die without fertilizers, nonorganic agriculture

40%

earth's crust

88 natural elements 9 most abudant/common: oxygen, silicon, aluminum, iron, calcium, sodium, magnesium, hydrogen

nuclear era

88 naturally occurring elements over 300 known isotopes about 40 isotopes are unstable- ejecting subatomic particles and stable nucleus. process known as radioactive decay (occurs alpha beta and gamma decay)

scanning tunnel microscope

Gerd binning and heincrick rohrer 1981 piezoelectricity- design scanning tunneling microscope found that schrodinger was right about atoms being spherical electron- mass 1, charge -1 proton- mass 1836x, charge 1 neutron- mass 1839x, charge 0

Ernest Rutherford (1871-1937)

Gold foil experiment-shot alpha particles towards thin piece of gold most particles passed through without being deflected concluded that plum pudding model was incorrect proposed that there was large empty area where electrons were scattered around and a small dense area where there were positive charged particles- protons

alpha decay

Helium nuclei- 4/2 He. 4 is the atomic mass, 2 atomic number equation for first radioactive decay of uranium-238 given as 238/92 U ----> 234/90 Th + 4/2 alpha or He balanced nuclear reaction alpha particles- positive charge, relatively massive, will not penetrate a piece of paper

periodic table

Johann Wolfgang doebereiner 1870-1849 law of triads- idea of periodicity, the tendency to occur in certain intervals chlorine bromine and iodine all have the same number of valence electrons Alexandre-Emile Beguyer de Chancourtois 1820-1866 first to arrange elements by atomic weight- Telluric Helix "properties of the elements are the properties of the numbers" could predict chemical reactions based on location

Non-proliferation treaty and Iran

NPT allowed 5 nations to have nuclear weapons- USA UK Russia China France Iran signed treaty 1968 to use nuclear power for civilian purposes FEB. 9th. 2003, Iran announced that they had a nuclear program at Natanz that was enriching uranium for power and research purposes

James chadwick (1891-1974)

Neutron detector alpha particles from source shot toward beryllium foil no deflection from magnet or electrons concluded there was third subatomic particle, neutron, which has no positive or negative charge and was massive

gun type weapon

The bomb when detonated: 1. temperatures rise extremely high 2. sound wave (sonic boom) 3. radioactive fallout used in bombing of Hiroshima WWII called "Little Boy" not much uranium needed for an effective weapon

JJ thompson 2nd experiment

determine whether charge was + or - concluded that charge of ray was negative because it bent upward towards the positive charge

Robert millikan (1868-1953)

addresses weakness in thompson's 3rd experiment millikan's experiment- shot oil droplets down can while tagging them with negative charge using x-ray when millikan turned up voltage of bottom plate he noticed that drops no longer fall to the bottom but separate at equal intervals. used vacuum oil- low viscosity drops suspended at different heights in the air concluded that he must have been adding finite number of electrons, for the oil droplets to be separated at equal intervals. concluded electrons very light because only a small # of charge was needed to separate them ===> electrons very light and negatively charged

atomic vs. hydrogen bomb

atomic-fission based hydrogen- fission and fusion

periodic trends

atoms get smaller from bottom to top and left to right largest atom Cs Cesium. Francium rare and highly radioactive

beta decay

beta particles are- negatively charged, relatively massless, known as an electron (not normal electron b/c an electron has to be in the orbitals of an atom) Beta particle is an electron whose origin is in the nucleus 1/0 n ----> 1/1 p + 0/-1 B + neutrino 234/90 Th ----> 234/91 Pa + 0/-1 B

nuclear fusion

bringing together. *sun. advantages- waste from fusion not dangerous, large supply, highly abundant challenges- requires extremely high temperatures, mixture becomes plasma like, no structure can contain plasma without being disintegrated

electromagnetic ion separation

calutrons developed to separate isotopes of uranium alpha and beta caultron

enrico fermi (1901-1954)

can create heavier particles by bombarding uranium atoms with neutrons would create beta particle and a heavier element-transuranium sent results to Otto hahn, fritz strassman, lise meitner for analysis on atomic mass -came across process known as nuclear fission, a type of radioactive decay that involves the splitting of the nucleus

second quantum number (azimuthal or angular momentum)

characterized by l tells you shape of orbital and what subshell electron is located in l=0 s orbital l=1 p orbital l=2 d orbital can have values of 0 1 2 3 4 ... (n-1)

implications of thompson's experiment

concludes that dalton's point that atoms were indivisible was incorrect atoms composed of some subatomic particles called negatively charged particles "corpuscles" (electrons George Johnstone Stoney) assumed that if there were positive charges there must be negative charges as well PLUM PUDDING MODEL, large spere filled with random distribution of positive and negative charges did not know whether corpuscles were heavily charged or super light

nuclear PWR plant

core of structure contains enriched uranium- uranium that contains more than the natural percentage of isotopic uranium occurrence of uranium-235 must be 3-7% in order to be enriched. natural abundance is .5% water and deuterium slow down the neutrons and act as a heat transfer- radioactive control rods made of cadmium metal lowered into the water to capture neutrons when solution gets too hot hot water transferred to turbine which will generate electricity

thompson 3rd experiment

determine properties of these particles ray moved by weak magnet concluded that particles of the ray were either very light or heavily charged b/c easily bent by weak magnet

one way inspectors can determine whether a country is making a nuclear weapon

if they are enriching uranium beyond a certain point

compression weapon

implosion weapon. one core surrounded by conventional explosives surrounding plutonium core "Fat Man" bombing of Nagasaki WWII

nuclear enrichment

inspectors need to find high levels of uranium enrichment to determine whether countries are making nuclear weapons process during WWII- gaseous diffusion, EMIS, thermal diffusion process today- gas centrifuge

non-proliferation treaty

international treaty signed to prevent the spread of nuclear weapons 5 nuclear powers: USA, UK, France, Russia, and China

Iran nuclear program

iran has admitted to processing uranium

Dr. mohammad el-barad

led team of inspectors to inspect Natanz and found 160 gaseous centrifuges, but blueprints for 50,000 more asked to inspect Kaalan-ye Electric company- looking for indications of a hidden nuclear power plant found highly enriched uranium samples. Iran claimed that the samples fell off centrifuges brought in from Pakistan. IAEA confirms that the uranium samples found in iran were a direct match to those found in pakistan.

erwin schrodinger

louis de broglie- electrons behave like a wave werner Heisenberg- uncertainty principle stated that it is impossible to know the precise location and momentum of an electron at a given instant formulated probability equation of describing where electrons are located

Third (magnetic) quantum number

m sub l tells you: 1. number of identical orbitals (orbitals with same average distance from nucleus) in subtle 2. orbital's orientation in space can have values of -l, (-l+1), (-l+2)... -1,0,1...(l-2), (l-1),l

Fourth quantum number

m sub s discovered by samuel goudsmit and george uhlenbeck discovered that electrons have spin because spherical charge on the electron is always spinning moving charge produces magnetic field no two electrons in an atom can have four identical quantum numbers, max # is 3- pauli's exclusion principle any one orbital can hold only 2 electrons

Niels bohr

model of the atom believed electrons were in more structured orbitals precursor to quantized energy levels in rutherford's model, electrons are in randomized and disorganized orbitals

first (primary or principle) quantum number

n tells you what shell the electron is in (how close to nucleus) n must always be positive integer 1 2 3 4 each row of periodic table represents principle quantum number energy of electron only dependent on principle quantum number En= -2.178 x 10^-18 (1/n^2) Joules

Iran

nuclear facilities: Nataanz and Kaalan-Ye Electric Plant highly enriched uranium samples found at both sites and matched to those found in pakistan.

human being element composition

oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus what makes gold different than silver? gold doesn't tarnish, silver does tarnish

uranium enriched past a certain point uranium not enriched past this point

past a certain point- bombs not past point- medical and energy uses

Lothar Meyer (1830-1895)

plotted the atomic masses of the atoms versus the atomic volume of the atoms and noticed periodicity

breeder reactors

plutonium-239 similar to uranium-235. fissile and can be bombarded with neutrons to release high amounts of energy problem- very long half life radioactive waste from breeder reactor extremely toxic

Positron

positive Beta particles, rare, dangerous Proton breaks down into a neutron and a positron 1/1 p ----> 1/0 n + 0/1 B positrons common for lighter atoms besides iodine carbon, potassium, nitrogen, oxygen, flourine, iodine

electron capture

produces x-rays electron from outer shell releases energy to replace electron. release of pure energy produces x-ray 202/81 Tl + 0/-1 e ----> 202/80 Hg + x rays Roentgen experiment- other process the produces x-rays- electron source (cathode ray) shot at larger nucleus, electrons begin to curve as it approaches nucleus. at curve, they slow down and give off energy. process produces x-rays

Gamma rays

pure energy can be accompanied by alpha or beta particle can affect human DNA and cause cancer excited state denoted by * 238/92 U ----> 234/90 Th* + 4/2 He (a) if a radioactive isotope releases low energy alpha particles it is dangerous

ELECTRON CONFIGURATION

review in notes

shapes of orbitals

s orbital- sphere. p orbital- dumbell. d orbital- clover leaf

current atomic theory

size of atom nucleus 10^-13 cm wide electron shell of atom 10^-8 cm wide and approx. 100,000 times larger than nucleus shows electrons as fuzzy border which shows probability of electron locations

hemispherical uranium pellets

small ones-nuclear power plants large ones-nuclear weapons

nuclear enrichment with UF6

solids with high vapor pressures have low boiling points shape is octahedral Oak ridge WWII enriching uranium: thermal diffusion, gaseous diffusion, electromagnetic isotope separation (EMIS)

Nuclear shell theory

there are certain shells in the nucleus that when filled leads to stability. placing both neutrons and protons into their respective shells leads to even greater stability if it has magic number of protons and neutrons- double magic. Helium Pb has magic # of protons in U decay series

world war II

thermal diffusion, gaseous diffusion, and electromagnetic ion separation were used to enrich uranium. abandoned and replaced by gaseous centrifugation

thermal + gaseous diffusion

thermal- convection currents gaseous-

stable vs. unstable nuclei

unstable nuclei- large, certain # of unstable p/n

elements names

usually named/symbol of first two letters of their name exceptions Cl- chlorine, Ag-silger, Au-gold based off of their latin names

hund's rule

when there are degenerate orbitals (orbitals at identical energy levels) in a shell, you must fill each of them first with one electron before pairing the second electron

Marie curie (1867-1934)

won nobel prize w husband pierre and Becquerel 1903 won another for discovery of Radium and Polonium Pierre curie won nobel prize for discovering piezoelectricity

Nuclear chemistry Wilhelm Roentgen (1845-1923)

worked with Lenard tube, x-rays. cathode rays, cardboard. energy source hitting screen... called them x-rays to stand for unknown energy wife put her hand between screen and tube, put film on screen and saw x-ray of her hand main reason x-rays formed was due to metal plate. when electrons hit metal plate, x-rays are formed

Antoine Henri Becquerel (1852-1908)

wraps rock in film and puts in drawer discovers that uranium is always emitting energy radioactive decay- concept that certain atoms are always falling apart and emitting energy