Flashcards in Chemistry Final Deck (141):
Number of Protons
Protons + Neutrons, depends on which isotope you are talking about (mass number varies in each element)
Weighted average atomic mass of the isotopes
Different isotopes of Hydrogen
Atomic Number--at the bottom (protons), Mass Number--at top, P+N
Unequal numbers of protons and electrons, cations (+) anions (-)
a type of nuclear change in which a target nucleus is bombarded by a neutron. The unstable nucleus should have split up in fission products and a few neutrons
Energy is given off in a nuclear fission reaction, E=mc^2 (c=speed of light, 3 X 10^8 m/s), matter is converted to energy (mass of product is less than mass than the original mass), deltaE=deltamc^2
What does a negative change in energy mean?
Heat is lost, so heat is given off
refers to any reaction in which one of the products becomes a reactant and thus makes t possible for the reaction to become self-sustaining
the amount of fissionable fuel required to sustain a chain reaction
Neutron absorbers, controls rate of reaction. Rods are lowered as fuel rods are inserted to slow down, as more U-235 is used, the rods are raised to continue the heat that is given off. Can be positioned to absorb fewer or more neutrons, rate of reaction depends on the position of the control rods
a liquid that comes in direct contact with the fuel bundles and control rods and carries away the heat. The coolant many times has boric acid, the boron atoms absorb neutrons and thus control the rate of fission and the temperature. The solution slows neutrons, thus making it more effective in producing fission
the water in the steam generators that don't come in contact with the reactor. Transfers heat from the primary coolant to drive the turbine
spontaneous change in which unstable nuclei decay
requires a neutron to break apart a relatively unstable nucleus into two nuclei (of abut the same size)
Who first discovered radioactivity?
penetrates the least (blocked by a sheet of paper), helium (4/2He), positively charged particle emitted from nucleus, 2 protons, 2 neutrons, and a 2+ charge
penetrates more (blocked by a book) electron (0/-1e-), a hih speed electron emitted from the nucleus, has a negative 1 charge, mass number stays the same, atomic numer increases by 1
the most penetrating (blocked by lead), emitted from the nucleus and has no charge or mass, it is a high-energy, short-wavelength photon.
Beta particle -- where does the electron come from?
It comes from a neutron
What makes isotopes stable/less stable?
Has to do with ratio of protons:neutrons
Isotopes above band of stability?
Undergoes Beta emission
Isotopes below band of stability?
Undergoes Alpha emission, has too many protons not enough neutrons
operator error, the cooling water was disrupted, messed up a test, the fuel rods got too hot/gave too much heat, the chemicals around the fuel rods got too hot and caught on fire
Nuclear waste on cooling site couldn't be kept cool, so waste pool leaked out
T/F: One of the biggest problems with Nuclear Power plants is the storage of the spent fuel cells
Two ways to deposit High-Level Nuclear Radioactive Waste
Storage on/near surface (distributed or centralized) or geological repository (open or sealed)
Greatest single source of background radiation?
Largest source of background radiation: natural sources or human-made sources
What is a free radical?
A highly reactive chemical species with one or more unpaired electrons
What units are used to measure radiation?
Curie (Ci)-used to measure how much radiation that is coming out of a sample, Sievert (Sv)-unit that relates to the amount of radiation energy that is absorbed by tissue
U.S. average of total annual radiation dose?
3600 microSieverts/yr, so .0036 Sv
What is ionizing radiation?
It's a type of radiation that collides with matter in such a way as to eject electrons from bonds
The cumulative effect of daily smoking exposes you to more radioactive material a year
does the most damage to the tissue but does the least penetrating power. Can be very bad if it is inside the body-inhaled, etc.
More penetrating power, but not cause as much damage. It can penetrate skin. Dose intermediate damage
can penetrate skin, can cause tissue damage (can kill cancer cells), breaks bonds
the time required for the level of radioactivity to fall to one-half its value
How much remains after 1 1/2 life? 2 1/2 lives?
In terms of carbon dating, do dead organisms exchange carbon with the atmosphere?
Convert non-fissionable U-238 into fissionable Pu-239. Pu-239 could be used to build nuclear weapons, it coverts spent fuel rods into useful fuel, Pu-239 cannot easily penetrate human skin but can be easily inhaled
Which coolant in a nuclear power plant is the one most likely to contain boric acid?
The fundamental diﬀerence between a nuclear power plant and a conventional power plant is
the source of heat
Which is the heaviest of the common radioactive particles?
a means of estimating the amount of biologically productive space (land, water, and sea surface) necessary to support a particular standard of living or lifestyle. The footprint for the US is 9.7 hectares per person, where as the global average is 2.7 hectares per person. The carbon footprint is a term used to describe how much carbon in the form of carbon dioxide an individual or society produces based on lifestyle choices.
a phrase that is juxtaposed to the phrase cradle-to-grave. Cradleto-grave is the approach to analyzing the life cycle of an item, starting with the raw materials from which it came and ending with its ultimate disposal someplace, presumably the Earth. Cradle-to-cradle refers to a regenerative approach to the use of things in which the end of the life cycle of one item dovetails with the beginning of the life cycle of another, so that everything is reused rather than disposed of as waste.
Meeting the needs of the present without
compromising the ability of future generations to meet their needs
Carbon-14 undergoes radioactive decay. This means that there is a change in
the number of protons and/or neutrons in the nucleus.
What best summarizes why a nuclear power
plant cannot explode like a nuclear bomb?
A critical mass of ﬁssionable material is
A nuclear power plant cannot undergo a nuclear explosion because
U is too dilute to produce a runaway reaction
A breeder reactor converts
nonﬁssionable U-238 to ﬁssionable Pu-
Which would contribute most to your annual
smoking a pack and a half of cigarettes
What is the maximum one-time dose of radiation one can receive without suﬀering any
detectable physiological eﬀects?
25 rem (0.25 Sv)
you started with 100.0 g of carbon-14, how
much would remain after 4 half-lives?
The purpose of the control rods is to
absorb neutrons given oﬀ in the ﬁssion
In nature, one element can change to another
by the process of
I emits a β particle, what nuclide is
A factor of 1.0×10^−6 corresponds to the preﬁx
A factor of 1.0×10^−3 corresponds to the preﬁx
A factor of 1.0×10^−9 corresponds to the preﬁx
The preﬁx centi means
What is the primary component of an exhaled breath?
The major component of our atmosphere is
Approximately what percentage of the
Earth’s crust is composed of oxygen?
What is the most appropriate concentration unit used to express the concentration
of a pollutant that has a concentration of
A sample of air is analyzed and found to contain 0.0002 g of particulate matter in 40 m3 of air. What is the concentration of particulate matter?
Sugar dissolved in water is
a homogeneous mixture.
What is one diﬀerence between a mixture and a compound?
A compound can only be separated into
its components by chemical means
A bar of deodorant soap is a/an
Steam coming from a pan of boiling water is
A sample of copper is a/an
Carbon monoxide is dangerous (even lethal)
displaces oxygen from the blood
Which substance is most dangerous to
breathe, owing to its lack of odor?
the eﬀect of a substance on health.
In which layer of the atmosphere are hikers
when they stand on the summit of Mt. Everest?
A pure substance composed of two or more elements chemically combined is
Mixtures are divided into two classes based on their appearance. What are these two classes?
heterogeneous or homogeneous
The smallest part of an element which can be recognized as that element is
Compounds formed between two nonmetals will have which bond?
A catalytic converter
completes the oxidation of CO and unburned hydrocarbons and reduces NOx to N2 and O2.
What is considered a secondary pollutant?
Which approach would reduce ALL forms of
indoor air pollution?
increasing the indoor/oudoor air exchange
Methane is the common name for which formula?
Ammonia is the common name for which formula?
What is the formula of titanium(IV) oxide?
Consider the bonds in iron(III) oxide. Are the
bonds more ionic or more covalent?
The attractions between anions and cations
in a crystal are known as
Elements with similar chemical properties are arranged in the same
one billion of a meter (1E10^-9)
Electromagnetic Spectrum (from shortest wavelength to longest)
gamma, X-rays, UV, visible, IR, microwave, radio
Electromagnetic spectrum (from longest to shortest wavelength)
radio, microwave, IR, Visible, UV, X-Rays, Gamma rays
Wavelength (in nanometers) of visible
Purple -- short or long?
short, 400 nm
Red -- short or long?
long, 700 nm
UV, X-Rays, Gamma Rays
frequency (v) formula
speed of light (c) / wavelength (lambda) in meters
relationship between frequency and wavelength
Energy (E) formula
(h*c) / wavelength (lambda) or h*v
speed of light
3 X 10^8 m*s^-1
Planck's Constant (h)
6.626 X 10^-34 Js
Energy's relationship to wavelength?
inversely proportional, as wavelength
Green, Red, Violet, Yellow. In order of increasing energy per photon
violet > green > yellow > red
What happens to UV-C?
absorbed in the upper atmosphere, both oxygen and ozone absorb light of these wavelengths
O2 --> UV photon
2 O, O2 + O--> O3
Easier to break: O2 or O3
the first set of natural steady-state
<2 (low) to 11+ (high)
How is ozone formed? (Basic formula)
Energy + 3 O2
Formula for number of shared electrons?
Shared Electrons = Needed - Actual
Formula for formal Charge
FC = Valence - (# of electrons + 3 of bonds)
280-320 nm, most UV-B is absorbed by O3 in the stratosphere
320-400least damaging, reaches Earth's surface in greatest amount
B - needs 6, Be - 4, H - 2
amount of UV radiation reaching a detector at ground level is correlated to the amount of ozone in column
c = ... (in terms of v and lambda)
v * lambda
when will molecular geometries be different?
When there are lone pairs on the central atom
3 electron regions
4 electron regions
5 electron regions
6 electron regions
unit for molar mass?
1 mol =
6.02E23 atoms = 1 mol
Most carbon found where?
in deep oceans
By what could a 300 nm photon be absorbed?
O3 but not O2
A gasoline’s octane rating is
a measure of the gasoline’s resistance to
causing knocking in a vehicle’s engine
the breaking of larger molecules into
increases the rate of a chemical reaction
but is not consumed in the process.
What two fuels from wood, octane, anthracite, methane, and garbage are the best as far as energy ouput per unit mass?
octane and methane
Approximately what percentage of electricity generated in the US is hydroelectric?
Soft lignite (brown coal) is the lowest grade of coal. Its chemical composition, and hence its heat of combustion, is most similar to that of
What is NOT a consideration when selecting
a substance to be used as a fuel?
It must burn inside an internal combustion engine
When coal burns
chemical energy is converted to heat energy
The separation of a mixture of compounds
into the individual components is called
A compound that has replaced tetraethyllead
as an octane booster is
methyl tert-butyl ether