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Chemistry
Q:
Which of the following is not a chemical?
A) salt
B) water
C) light
D) carbon dioxide
E) sugar
Q:
One example of a chemical used in toothpaste is
A) chlorine.
B) sulfur.
C) carbon dioxide.
D) calcium carbonate.
E) sugar.
Q:
In this list, which substance can be classified as a chemical?
A) salt
B) sleep
C) cold
D) heat
E) temperature
Q:
Water, H2O, is an example of a(n)
A) chemical.
B) solid.
C) wave.
D) electric charge.
E) element.
Q:
Explain the treatment named boron neutron capture therapy (BNCT).
Q:
Explain the difference between 1 rad and 1 rem of radiation..
Q:
Neutron ________ analysis is a non-destructive process in which a sample is irradiated with neutrons. The neutrons react with nuclei to form isotopes with masses one unit higher than the original nuclei. The nuclei are formed in excited states and they emit gamma radiation that can be used to both identify the presence of an element and quantify how much is present.
Q:
A unit used to quantify biological damage is called the ________ or rem.
Q:
Technetium-99m is routinely used in medical imaging. The italics m means the nucleus is ________.
Q:
All isotopes of atomic number greater than ________ are unstable and radioactive.
Q:
Which of the following statements concerning neutron activation analysis is/are CORRECT?
1/ In neutron activation analysis, a neutron is ejected from an atom creating a new isotope that is one mass unit lower.
2/ Neutron activation analysis is destructive, but requires less than 1 g of sample.
3/ Neutron activation analysis creates isotopes in the excited state that emit gamma rays to return to the ground state.
A.1 only
B.2 only
C.3 only
D.2 and 3
E.1, 2, and 3
Q:
In boron neutron capture therapy (BNCT), boron-10 is injected into a tumor. When the tumor is irradiated with neutrons, boron nuclei capture the neutrons and disintegrate into two particles. These particles are lithium-7 and a(n) ____.
A.alpha particle
B.beta particle
C.positron
D.deuterium nuclei
E.helium nuclei
Q:
In positron emission tomography (PET), a positron emitted from an unstable isotope travels a short distance before it is annihilated by
A.an electron, creating a proton that is detected by the instrument.
B.a neutron, creating two gamma rays that travel in opposite directions.
C.an electron, creating two gamma rays that travel in opposite directions.
D.an alpha particle, creating two protons that travel in opposite directions.
E.gamma ray, creating an electron that is detected by the instrument.
Q:
Which of the following isotopes is used in the treatment of thyroid disorders?
A.
B.
C.
D.
E.
Q:
Which of the following types of radiation has the greatest quality factor?
A.beta particles
B.alpha particles emitted within the body
C.gamma rays
D.low energy protons
E.low energy neutrons
Q:
The becquerel is an SI unit for the measurement of radiation. One Bq represents
A.1 J energy absorbed per kg of tissue.
B.3.7 1010 disintegrations per second.
C.1 disintegration per second.
D.0.01 J energy absorbed per kg of tissue.
E.1 calorie energy absorbed per kg of tissue.
Q:
Which of the following statements concerning radiation absorption by living tissue is/are CORRECT?
1/ The "quality factor" takes into account the differences in damaging power of the various forms of radiation.
2/ One gray denotes the absorption of 1 joule per kilogram of tissue.
3/ The SI unit for biological damage is a sievert (Sv), which is determined by multiplying grays by the quality factor.
A.1 only
B.2 only
C.3 only
D.2 and 3
E.1, 2, and 3
Q:
At the high temperatures necessary for fusion, matter exists as a plasma, which is
A.a liquid form of a radioactive element.
B.a gaseous cloud of electrons and positrons.
C.a mixture of unbound nuclei and electrons.
D.an equal mixture of matter and anti-matter.
E.a dense solid composed of neutrons.
Q:
What percentage of the world's electricity is supplied by nuclear fusion reactors?
A.0%
B.3%
C.8%
D.17%
E.39%
Q:
What particle(s) are produced in the following reaction? A.
B.
C.
D.
E.
Q:
Complete the following fusion reaction. A.
B.
C.
D.
E.
Q:
Which of the following elements undergoes nuclear fusion to provide the primary source of energy from the sun?
A.helium
B.uranium
C.hydrogen
D.carbon
E.boron
Q:
Which three steps, placed in the proper order, are required for a nuclear chain reaction?
A.propagation, equilibration, and termination
B.propagation, oxidation, equilibration
C.equilibration, propagation, termination
D.initiation, oxidation, propagation
E.initiation, propagation, and termination
Q:
What role do the cadmium control rods play in a fission reactor?
A.The rods control the rate of fission by absorbing neutrons.
B.The cadmium combines with spent uranium fuel to produce a non-radioactive product.
C.The rods focus the neutrons toward the center of the reactor.
D.The cadmium acts as a catalyst, enabling fission to occur at lower temperatures.
E.The rods move forward and backward, driving the pistons that turn the turbines.
Q:
Which two nuclei are the two fissionable isotopes most commonly used in nuclear reactors?
A. and B. and C. and D. and E. and
Q:
One means of enriching the percentage of uranium-235 for use as nuclear fuel is ____.
A.liquid distillation
B.gaseous centrifugation
C.mass spectroscopy
D.gamma ray bombardment
E.ion chromatography
Q:
Complete the following fission reaction. A.
B.
C.
D.
E.
Q:
Which of the following statements is/are CORRECT?
1/ Naturally occurring isotopes account for only a small fraction of known radioactive isotopes.
2/ A few radioactive isotopes with long half-lives, such as U-235 and U-238, are found in nature.
3/ Trace quantities of some short-lived radioactive isotopes, such as C-14, are found in nature because they are formed continuously by nuclear reactions.
A.1 only
B.2 only
C.3 only
D.1 and 2
E.1, 2, and 3
Q:
Which of the following statements is/are CORRECT?
1/ The transuranium elements are created in a nuclear reaction sequence that begins with bombardment of a lighter nucleus with low energy helium nuclei.
2/ A low energy neutron may be captured by a nucleus, giving a product in which the mass number is increased by one unit.
3/ Nuclear reactions involving neutron capture followed by gamma ray emission are referred to as (n, g) reactions.
A.1 only
B.2 only
C.3 only
D.2 and 3
E.1, 2, and 3
Q:
A sample of phosphorus-32 is found to have an activity of 885 disintegrations per hour (dph). After 25 hours the activity has decreased to 841 dph. What is the rate constant for the decay of phosphorus-32?A.0.0038 hr-1B.0.0020 hr-1C.0.15 hr-1D.490 hr-1E.0.12 hr-1
Q:
The number of disintegrations per minute (dsm) of a sample of iodine-133 is measured at 5.5 102 dsm. When the sample is measured 295 minutes later, the number of disintegrations has decreased to 4.7 102 dsm. What is the half-life of iodine-133?A.5.7 10-4 m.B.2.6 m.C.1.3 103 m.D.3.9 102 m.E.9.7 104 m.
Q:
is used in many home smoke alarms. If 85% of the americium in a smoke detector decays in 1250 years, what is the half-life of this isotope?A.1.52 10-3 yrB.7.35 102 yrC.5.33 103 yrD.5.78 103 yrE.4.57 102 yr
Q:
The rate constant for the decay of copper-62 is 9.8 minutes-1. What is the half-life of this isotope?
A.0.071 m.
B.1.6 m.
C.14 m.
D.0.10 m.
E.9.8 m.
Q:
Uranium-235 has a half-life of 7.04 108 years. How many years will it take for 99.9% of a U-235 sample to decay?
A.7.0 105 yr
B.1.0 106 yr
C.4.7 109 yr
D.4.9 109 yr
E.7.0 109 yr
Q:
The half-life of carbon-14 is 5730 years. If a sample initially contains 2.67 mg carbon-14, what mass remains in the sample after 2.40 104 years?
A.0.0 mg
B.0.17 mg
C.0.92 mg
D.0.15 mg
E.0.64 mg
Q:
The half-life of mercury-203 is 46.6 days. What percentage of mercury-203 remains in a sample after 365 days?
A.3.72 10-4 %
B.0.439%
C.1.49%
D.5.43%
E.12.8%
Q:
The half-life for the spontaneous decay of technetium-99m is 6.0 hours. How much of a 0.20 g sample of this isotope remains after 4.5 hours?
A.0.05 g
B.0.08 g
C.0.12 g
D.0.15 g
E.0.20 g
Q:
Lead-200 has a half-life of 21.5 hours. Starting with 3.77 mg of this isotope, how much would remain after 72 hours?
A.0.0 mg
B.0.098 mg
C.0.37 mg
D.0.47 mg
E.1.1 mg
Q:
Calculate the energy released (per mole of deuterium consumed) for the following fusion reaction, given the following molar masses of nucleons and nuclei. (c = 2.998 108 m/s)
particle mass (g/mol)
proton 1.007825
neutron 1.008665
deuterium 2.0140
tritium 3.01605
helium-4 4.00260
A.5.63 106 J/mol
B.1.69 1015 J/mol
C.4.62 1013 J/mol
D.8.44 1011 J/mol
E.1.69 1012 J/mol
Q:
The molar nuclear mass of fluorine-19 is 18.99840 g/mol. The molar mass of a proton is 1.007825 g/mol. The molar mass of a neutron is 1.008665 g/mol. Calculate the binding energy (in J/mol) of F-19. (c = 2.998 108 m/s)
A.6.753 1012 J/mol
B.7.131 1012 J/mol
C.1.426 1013 J/mol
D.8.609 1014 J/mol
E.8.538 1014 J/mol
Q:
The point of maximum stability in the binding energy curve occurs in the vicinity of which one of the following isotopes?
A.
B.
C.
D.
E.
Q:
A plot of the number of neutrons versus the number of protons in nuclei shows a narrow band of stable isotopes. Isotopes with a low proton-neutron ratio (i.e., ones that fall below the band of stability) decay by
A.positron emission or electron capture.
B.positron emission or alpha emission.
C.beta emission or electron capture.
D.gamma ray emission or beta emission.
E.neutron capture or alpha emission.
Q:
All of the following statements concerning nuclei are true EXCEPT
A.only hydrogen-1 and helium-3 have more protons than neutrons.
B.from He to Ca, stable nuclei have roughly equal numbers of protons and neutrons.
C.elements with odd atomic numbers have more stable isotopes than do those with even atomic numbers.
D.the neutron to proton ratio in stable nuclei increases as mass increases.
E.more stable isotopes have an even number of neutrons than an odd number.
Q:
By what (single step) process does osmium-185 change to rhenium-185?
A.a particle emission
B.b particle emission
C.gamma ray emission
D.electron capture
E.neutron capture
Q:
By what (single step) process does americium-241 decay to neptunium-237?
A.a particle emission
B.b particle emission
C.positron emission
D.electron capture
E.neutron capture
Q:
Write a balanced reaction for the decay of barium-127 by positron emission.
A.
B.
C.
D.
E.
Q:
What nucleus decays by beta emission to produce antimony-121?
A.
B.
C.
D.
E.
Q:
What nucleus is produced if thorium-225 decays by electron capture?
A.
B.
C.
D.
E.
Q:
If astatine-207 decays by a emission, followed by a emission, followed by electron capture, what nucleus is produced?
A.
B.
C.
D.
E.
Q:
What nucleus decays by successive b, b, a emissions to produce uranium-236?
A.
B.
C.
D.
E.
Q:
If a nucleus decays by successive a, b, b particle emissions, its atomic number will
A.decrease by four.
B.decrease by two.
C.increase by four.
D.increase by two.
E.be unchanged.
Q:
If a nucleus gains a neutron and then undergoes beta emission,
A.its atomic number decreases by one and its mass number increases by one.
B.its atomic number is unchanged and its mass number increases by one.
C.both its atomic number and its mass number are unchanged.
D.its atomic number increases by one and its mass number is unchanged.
E.its atomic number increases by one and its mass number increases by one.
Q:
If a nucleus emits an alpha particle
A.its atomic number decreases by four and its mass number decreases by two.
B.its atomic number decreases by two and its mass number decreases by four.
C.its atomic number increases by two and its mass number decreases by two.
D.its atomic number is unchanged and its mass number is unchanged.
E.its atomic number is unchanged and its mass number decreases by four.
Q:
If a nucleus undergoes beta particle emission
A.its atomic number decreases by four and its mass number decreases by two.
B.its atomic number decreases by two and its mass number decreases by four.
C.its atomic number increases by one and its mass number is unchanged.
D.its atomic number decreases by one and its mass number increases by one.
E.its atomic number is unchanged and its mass number decreases by one.
Q:
Which of the following reactions is an example of electron capture?
A.
B.
C.
D.
E.
Q:
Which of the following reactions is an example of positron emission?
A.
B.
C.
D.
E.
Q:
What is the charge on a beta particle?
A.+2
B.+1
C.0
D.-1
E.-2
Q:
Which of the following types of radiation will pass through a piece of paper, but will be stopped by 0.5 cm of lead?
A.a
B.b
C.
D.g
E.All of the above will pass through 0.5 cm of lead.
Q:
Which symbol represents a beta particle?
A.
B.
C.
D.
E.
Q:
Which of the following is the most penetrating form of radiation?
A.a
B.b
C.
D.g
E.All of the above are equally penetrating.
Q:
The complex ion [NiCl4]2- is paramagnetic, but the complex ion [Ni(NH3)4]2+ is diamagnetic. Why do the magnetic properties of these two nickel complexes differ?
Q:
EDTA4-, a hexadentate ligand, is most effective at chelating metal ions when the pH is greater than 12. Explain why low pH decreases the chelating ability of the ligand.
Q:
Phenanthroline (C12H8N2) can bind to metal ions using both its ammine groups. It is referred to as a(n) ________ ligand, meaning it is "two-toothed."
Q:
One method of recovering metals from their ores involves aqueous solutions; a second method involves heat. The method involving heat is called ________.
Q:
The period 6 transition metals have greater densities than either the period 4 or 5 transition metals. An explanation concerns the 4f orbitals, which are filled with electrons just prior to the 5d orbitals. As the 4f orbitals are filled, the radii of the elements decrease. The decrease in size is referred to as the ________ contraction.
Q:
According to the effective atomic number rule, Ru(0) should coordinate to ____ carbonyl ligands.
A.4
B.5
C.6
D.7
E.8
Q:
According to the effective atomic number rule, Mo(0) should coordinate to ____ carbonyl ligands.
A.4
B.5
C.6
D.7
E.8
Q:
The effective atomic number (EAN) rule states that organometallic coordination compounds are likely to be stable if
A.the oxidation state of the metal is zero.
B.the sum of the metal valence electrons plus the electrons donated by the ligand equals 18.
C.the ligand field splitting is small.
D.the metal has an even atomic number.
E.the metal has an odd atomic number.
Q:
The spectrochemical series
A.lists ligands in order from monodentate to hexadentate.
B.lists ligands in the order of their electronegativity.
C.lists coordination compounds in order of their color.
D.lists complex ions in order of their color.
E.lists ligands in order of their tendency to split d orbitals.
Q:
All of the following complexes will be colored (in the visible) EXCEPT ____.A.[Co(en)3]2+B.[Fe(CN)6]4-C.[Ni(H2O)6]2+D.[Sc(NH3)6]3+E.[Cu(NH3)4]2+
Q:
Determine the number of unpaired electrons in a Cu(II) tetrahedral complex.
A.0
B.1
C.2
D.3
E.4
Q:
Determine the number of unpaired electrons in the tetrahedral complex ion [Co(NH3)4]2+.
A.0
B.1
C.2
D.3
E.4
Q:
As bound ligands, which of the following causes the largest splitting of d-orbitals?A.phenB.H2OC.I-D.CN-E.C2O42-
Q:
If an octahedral iron(II) complex is diamagnetic, which of the following sets of conditions best describes the complex?
A.low-spin, D0 small
B.low-spin, D0 large
C.high-spin, D0 small
D.high-spin, D0 large
E.none of these
Q:
Determine the number of unpaired electrons in an octahedral, high-spin Cr(II) complex.
A.1
B.2
C.3
D.4
E.5
Q:
What is the number of unpaired electrons in an octahedral, low-spin Mn(II) complex?
A.0
B.1
C.2
D.3
E.4
Q:
What is the number of unpaired electrons in an octahedral, high-spin Co(III) complex?
A.1
B.2
C.3
D.4
E.5
Q:
All of the following statements concerning crystal field theory are true EXCEPT
A.in low-spin complexes, electrons are concentrated in the dxy, dyz, and dxz orbitals.
B.in an isolated atom or ion, the five d orbitals have identical energy.
C.low-spin complexes contain the maximum number of unpaired electrons.
D.the crystal field splitting is larger in low-spin complexes than high-spin complexes.
E.the energy difference between d orbitals often corresponds to an energy of visible light.
Q:
In an octahedral complex, electrons in and orbitals experience a greater repulsion from the lone pairs of electrons on ligands because these orbitals
A.contain more electrons than the other three d orbitals.
B.each contain one unpaired electron.
C.are oriented directly toward the incoming ligand electron pairs.
D.are located a greater distance from the metal ion nucleus.
E.are roughly spherical in shape, much like an s orbital.
Q:
Which of the following statements is/are CORRECT?
1/ Complex ions with the structure [ML2]n are always linear.
2/ Complex ions with the structure [ML6]n are always octahedral.
3/ Complex ions with the structure [ML4]n are always square planar.
A.1 only
B.2 only
C.3 only
D.1 and 2
E.2 and 3