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92 Cards in this Set

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Atomic nuclei are made of these two things
Protons
neutrons
What are protons and neutrons called collectively?
Nucleons
In nuclear chemistry what is an atom referred to as?
A nuclide
How is an atom identified in nuclear chemistry?
By the number of protons and neutrons in its nucleus.
Simple, What is an atom made up of?
Protons,neutrons, and electrons
Because an atom is made of prtons,neutrons,and electrons you might expect this mistakenly?
That the mass of an atom be the same as the mass of an equal number of isolated, protons,neutrons, and electrons.However this is not the case
Mass defect is ...
The difference between the mass of an atom and the sum of the masses of its protons, neutrons, and electrons.
Albert Einstein's equation of E=Mc˛ answers this question
What causes the lost in mass?
According to Albert Einstein's equation mass can be...
Mass can be converted to enerygy and energy to mass.
The mass defect is caused by...
The conversion of mass to energy upon the formation of the nucleus.
Nuclear binding energy is...
The energy released when a nucleus is formed from nucleons.
Nuclear binding energy can also be thought of as energy required to do this...
The amount of energy required to break apart the nucleus.
Therefore, the nuclear binding energy is also a measure of the _______ of a nucleus.
Stability
This is used to compare the stability of different nuclides.
The binding energy.
The binding energy per nucleon is...
The binding energy of the nucleus divided by the number of nucleons it contains.
The higher the binding energy per nucleon then...
The more tightly the nucleons are held together.
Elements with intermediate atomic masses have...
The greatest binding energies per nucleon and are therefore the most stable.
Stable nuclides have_____ characteristics...
Certain characteristics.
A beltlike graph is obtained when...
When the number of protons in stable nuclei is plotted against the number of neutrons
The band of stability is...
When the stable nuclei cluster over a range of neutron-proton ratios
Among atoms having low atomic numbers, the most stable nuclei are those with a neutron-proton ratio of approximately this
1:1 are the most stable
Protons in a nucleus repel...
but....
All other protons through electrostatic repulsion

but the short range of nuclear forse allows them to attract only protons very close to them.
As the number of protons in a nucleus increases, the electrostatic force between the protons in the nucleus also ______ faster than the this _______ and do this to the nucleus.
Increases
nuclear force
stabilizes the nucleus
83 is this on the periodic table
Bismuth
Stable nuclei tend to have this types of numbers of nucleons.
Even numbers of nucleons.
Out of the 256 stable nuclides ____ have even numbers of protons and neutrons.
159
The stability of a nucleus is greatest when the nucleons-like electrons- are ______.
Paired
According to the nuclear shell model....
Nucleons exist in different energy levels or shells in the nucleus.
The numbers of nucleons tht represent completed nuclear energy levels are called....
magic numbers
Unstable nuclei undergo _____ change that change their number of _____ and ___.
Spontaneous change
Protons and neutrons
In the process of this spontaneous change, unstable nuclei give off _____ amounts of energy and ____ their stability.
large amounts of energy
increase their stability
A nuclear reaction is....
A reaction that affects the nucleus of an atom.
In equations representing nuclear reactions, the total amounf of atomic numbers must be equal to _______ on both sides of the equation.
total of the atomic numbers=the total of the mass numbers
The identity of an element changes when...
The atomic number changes
A transmutation is ...
A change in the identity of a nucleus as a result of a change in the number of its protons.
Radioactive decay was first discovered by...
Henri Becquerel
Radioactive decay is...
The spontaneous disintegration of a nucleus into a slightly lighter nucleus,accompained by emission of particles,electromagnetic radiation, or both.
What is nuclear radiation...
Particles or electromagnetic radiation emitted from the nucleus during radioactive decay.
Uranium is a ______ nuclide.
Radioactive
Radioactive nuclide is ....
An unstable nucleus that undergoes radioactive decay.
They disovered two new radioactive elements...
The Curies
The two new elements that the Curies discovered were _____ and _____
Polonium and radium
Thorium is _______
Radioactive
All nuclides beyond atomic number 83 are .....
unstable and radioactive
A nuclide's type and rate of decay depend on the _____ content and the ______ level of the nucleus.
The nucleon content and the energy level of the nucleus.
An alapha particle is....
Two protons and two neutrons bound together and is emitted from the nucleus during some kinds of radioactive decay.
A beta particle is ...
An electron emitted from the nucleus during some kinds of radioactive decay.
Elements above the band of stability are unstable because they have too many...
neutrons
To decrease the number of neutrons, a neutron can be converted into a _____ or a ______
Into a proton or an electron
Elements below the band of stability have too many _____ to be stable
Too many protons
In electron capture...
An inner orbital electron is captured by the nucleus of its own atom.
According to the nuclear shell model, gamma rays are produced when...
Nuclear particles undergo transitions in nuclear -energy levels.
No two radioactive isotopes decay at what...
The same rate
Half life is...
The time required for half the atoms of a radioactive nuclide to decay.
More stable nuclides decay _____ and have ______ half-lives
more slowly and have longer half-lives
Less-stable nuclides decay very _____ and have _______ half lives
quickly and have shorter half lives
True/False one nuclear reaction is not always enough to produce a stable nuclide?
True may need more
A decay series is...
A series of radioactive nuclides produced by successive radioactive decay until a stable nuclide is reached.
The heaviest nuclide of each decay series is the...
parent nuclide
The nuclides produced by the decay of the parent nuclides are called....
daugther nuclides
Alll naturally occurring nuclides with atomic numbers greater than 83 belong to ____ of 3 natural decay series.
1
The parent nuclides are these three...
Uranium-238
Uranium-235
Uranium-332
Artificial radioactive nuclides are ...
Radioactive nuclides not found naturally on Earth.
Artifical radioactive nuclides are made by...
Artifical transmutations
Artificial transmutations are...
Bombardment of stable nuclei with charged and uncharged particles.
These can easily penetrate the nucleus...
Neutrons
Positively charges alpha particles,protons,and other ions are _______ by the nucleus.
Repelled
Radioactive isotopes of all natural elements have been produced by this process...
artificial transmutation
Transuranium elements are...
Elements with more than 92 protons in their nuclei
Transuranium elements are...
Elements with more than 92 protons in their nuclei.
Nuclear radiation included these three things...
alpha particles
beta particles
gamma rays
These rays have the greatest penetrating abilities...
gamma rays
The roentgen is...
A unit used to measure nuclear radiation
Ionization can ______ liviing tissue
Damage
Radiation damage to human tissue is measured in ...
rems
One rem is the quantity of ionizing radiation that does as much damage to human tissue as...
As done by 1 roentgen of high-voltage X rays.
Average enviromental background radiation exposure for people in the US is about...
0.1 rem per year
The maxium amount of radiation exposure is ...
0.5 rem
Every radioactive substance has a ....
half life
In nuclear fission...
A very heavy nucleus splits into more-stable nuclei of intermediate mass.
Missing mass converted into...
Energy
When uranium-235 is bombarded with slow neutrons it is made _____
unstable
What does rem stand for...
Roentgen equivalent man
A chain reaction is...
A reaction in which the material that starts the reaction is also one of the products and can start another reaction.
Critical mass is...
The minimum amount of nuclide that provides the number of neutrons needed to sustain a chain reaction.
Fission was 1st named by...
Lise Meitner
Fission is ....
The spillting of a heavy nucleus and releases tons of energy
Fusion is...
The joining of light nucli to join into one heavy nucleus
Radioactive decay was 1st discovered by him using Uranium.
Henri Becquerel
Beyond atomic number 83 on the periodic table the repulisive force of this is so great that...
No stable nuclides exist
The most stable nuclides are those having __,__,__,___,__ as # of protons or # of neutrons or their sum.
2,8,20,28,50,82,or 126
Only _____ nuclides have odd numbers of both protons and neutrons.
4