Lesson 6 Flashcards
is the study of reactions involving changes in atomic nuclei.
Nuclear Chemistry
Nuclear chemistry all started with the discovery of natural radioactivity by __________
Antoine Becquerel
All nuclei contain two kinds of fundamental particles, ____________
proton and neutron
Some nuclei are unstable; they emit particles and/or electromagnetic
radiation spontaneously and this is known as ________________
radioactivity.
All elements having an atomic number greater than __________ are radioactive.
83
The symbol 0 -1 e represents an electron in or from an ___________
atomic orbital.
The symbol 0 -1 betarepresents an electron that, although physically identical to any other
electron, comes from a _____________-
nucleus
The ________ has the same mass as the electron, but bears a +1 charge.
positron
The ____ particle has two protons and two neutrons, so its atomic number is 2 and its mass
number is 4.
α
The total number of protons plus neutrons in the products and in the reactants must be the
same (conservation of _____________).
The total number of nuclear charges in the products and in the reactants must be the same
(conservation of ___________).
-mass number
-atomic number
we know that like charges repel and unlike charges attract one
another. Protons to repel one another strongly.
coulumb’s law
If repulsion outweighs attraction, the nucleus ___________, emitting
particles and/or radiation.
If attractive forces prevail, the nucleus is ______.
-disintegrates
-stable
The principal factor that determines whether a nucleus is stable.
Neutron-to Proton Ratio (n/p) -
Stable atoms of elements having low atomic number has n/p value is close to ___
1
Nuclei that contain 2, 8, 20, 50, 82, or 126 protons or neutrons are generally more stable than nuclei
that do not possess these numbers. The numbers 2, 8, 20, 50, 82, and 126 are called ________
magic numbers
beta decay
decrease #of neutrons by 1
increase # of protons by 1
positron
increase # of neutrons by 1
decrease number of protons by 1
electron capture decay
increase # of neutrons by 1
decrease number of protons by 1
alpha decay
decrease # of neutrons by 2
decrease number of protons by 2
is the result from the bombardment of nuclei by neutrons,
protons, or other nuclei.
nuclear transmutation
- elements with atomic numbers greater than 92.
Transuranium elements
__________ made it possible to synthesize the so-called transuranium elements.
Particle accelerators
is the process in which a heavy nucleus (mass number. 200) divides to
form smaller nuclei of intermediate mass and one or more neutrons.
nuclear fission
The first nuclear fission reaction to be studied was that of ___________ bombarded with
slow neutrons, whose speed is comparable to that of air molecules at room temperature.
uranium-235
a self- sustaining sequence of nuclear fission reactions.
nucear chain reaction
the combining of small nuclei into larger ones, is largely exempt from
the waste disposal problem.
nuclear fusion
Nuclear fusion occurs constantly in the _______ because it is made up mostly of hydrogen and
helium.
sun
Because fusion reactions take place only at very high temperatures, they are often
called _________________.
thermonuclear reactions
thermonuclear reactions/nuclear fusion take place at extremely high temperatures, on the order of _____________ to overcome the repulsive forces between the nuclei.
100 million
degrees Celsius,
