Section 17.3- Nuclear Reactions Flashcards
nuclear equations must follow two important rules
- the mass number must be conserved
- the nuclear charge (atomic number) must be conserved
in nuclear equations, the _____________- are not used in the finding of the mass number and nuclear charge
electrons
two main types of radioactive decay
alpha decay
beta decay
a high-speed electron
beta decay
alpha decay and beta decay may involve the emission of high energy electromagnetic waves called
gamma rays
some other types of nuclear reactions may involve the EMISSION OF HIGH SPEED NEUTRONS as
neutron radiation
occurs when an unstable atom ejects a clump of two protons and two neutrons called an alpha particle in order to reach a more stable state
alpha decay
alpha decay is the most common type of decay in elements with
Z > 83
alpha particles are actually
2+ ions of helium-4
occurs when a neutron in an atom’s nucleus changes into a proton and emits and electron in the process
beta decay
the electron emitted from the nucleus
beta particle
the beta particle is identical to all other electrons except for its
origin
uses for beta decay
self-luminous watches
firearm sights
exit signs
electromagnetic waves of very high frequency and energy
gamma radiation
releases gamma radiation (electromagnetic waves of very high frequency and energy)
gamma decay
gamma decay often occurs in nuclei that have just undergone ______________ or are in an excited state
alpha or beta decay
uses for gamma decay
cancer treatment
types of nuclear reactions that cause neutron to be ejected from the nucleus, forming
neutron radiation
the chief use of neutron radiation is the
production of transuranium elements by bombardment reactions
the four types of radiation discussed vary greatly in their ability to
penetrate matter
lowest to highest order of decay penetration
- alpha
- beta
- gamma
- neutron
the decay rate of a substance can be stated as its
the length of time it takes for 1/2 of the original substance to decay into the new substance
half-life
the amount of nuclide remaining after each half-life is
one half of what you started with
to find the amount of nuclide remaining after a given time
- find the number of hlaf-lives contained in the given time period
- raise (.5) to the power of this number, and
- multiply the original mass of nuclide by the value obtained in step 2
an important principle to remember is that the half-life of a substance determines the
intensity of the radiation it produces
the amount of decay occurring in a radioactive substance is known as the
activity
is measured by counting the number of nuclear disintegrations that occur per second
the activity of radioactive nuclide
the SI unit of activity
defined as one nuclear disintegration per second
becquerel (bq)
the shorter the half-life, the ______________ the radioactivity
greater
because a Bq is a small unit, an older unit called __________ is still used
curie (Ci)
1curie (Ci) =
3.7 x 10 ^ 10 Bq
the new atom that results when an unstable atom undergoes nuclear decay
daughter element or daughter nuclide
the result of the process of seeking to find a stable nuclide through the production of daughter nuclides is a long series of radioactive nulcides ending in a nonradioactive (stable) nuclide; such a chain of nuclides is a
radioactive decay series
nuclear reactions induced by pelting a sample with other particles are called
bombardment reactions
uses magnetic and electric fields to accelerate charged particles to energies of several million electron volts to initiate nuclear reactions
particle accelerators
all the elements beyond uranium that have been artificially prepared by bombardment reactions, although some of them occur naturally by trace amounts
transuranium elements
