Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
40 Cards in this Set
- Front
- Back
|
Natural radioactivity
|
the spontaneous emission of particles or energy from an atomic nucleus as it disintegrates
|
|
|
Alpha particle
|
nucleus of a Helium atom, 2 p+ & 2 n0
|
|
|
Beta particle
|
high energy electron
|
|
|
Gamma ray
|
electromagnetic radiation of very short wavelength
|
|
|
Radioactive decay
|
the natural spontaneous disintegration or decomposition of a
|
|
|
nuclear force
|
a strong fundamental force, force of attraction that only works at very short distances
|
|
|
Protons and neutrons in the nucleus are in moving...
|
energy levels, or shells, just as the electrons are - some arrangements are more stable than others.
|
|
|
Generally… the nucleus is more stable if the protons and neutrons are both
|
in even numbers.
|
|
|
All isotopes with an atomic number greater than...
|
83 are unstable.
|
|
|
Nucleons
|
another term for protons and neutrons
|
|
|
atomic number, determines what element it is
|
Number of p+
|
|
|
can vary, represented as an isotope
|
Number of n0
|
|
|
Radioactive decay allows an unstable nucleus to become...
|
more stable with less energy.
|
|
|
Alpha emission
|
the release of an alpha particle from a disintegrating nucleus
|
|
|
Alpha emission
|
can travel 2-12 cm through the air
|
|
|
Beta emission
|
the release of a beta particle from a disintegrating nucleus, this process increases the number of protons in a nucleus
|
|
|
Beta emission
|
a neutron changes to a proton by emitting the electron
|
|
|
Beta emission
|
they are more penetrating and can travel several hundred centimeters in air
|
|
|
Gamma emission
|
the release of a high-energy burst of electromagnetic
|
|
|
Gamma emission
|
this can be caused from the other types of decay, once alpha or beta decay takes place, the nucleus is left in a high-energy state
|
|
|
Gamma emission
|
Nucleons don’t change in this type of emission
|
|
|
Gamma emission
|
most penetrating
|
|
|
Gamma emission
|
can be stopped by a piece of lead close to the source
|
|
|
Gamma emission
|
used to kill many parasites and bacteria in the foods we eat
|
|
|
Radioactive decay series
|
a process continuing through a series of decay reactions until a stable nucleus is achieved
|
|
|
Half-Life
|
the time required for 1/2 of the unstable nuclei to decay
|
|
|
Instruments for Measuring Radioactivity
|
Photographic film & Geiger counters
|
|
|
Radioactivity can be measured at
|
1.) the source of radioactivity & 2.) the place of reception, where radiation is absorbed
|
|
|
Activity of a source
|
a measure of the number of nuclear disintegration per unit of time
|
|
|
Units for measuring the activity of a source
|
curie (Ci) or Becquerel (Bq)
|
|
|
More specific measurements deal with amount of radiation received by humans is expressed in terms of radiological dose in units of...
|
rem.
|
|
|
A regular person in one day will receive about...
|
1 millirem
|
|
|
Background radiation
|
low amounts of radiation from natural sources
|
|
|
Nuclear fission
|
splitting a massive nucleus into more stable, less massive nuclei with the release of energy
|
|
|
Chain reaction
|
a reaction where the products are able to produce more reactions in a self-sustaining series
|
|
|
Critical mass
|
the mass and concentration of nuclei that is sufficient to sustain
|
|
|
Nuclear fusion
|
less massive nuclei coming together to form more stable and
|
|
|
One problem with developing nuclear fusion
|
1.) temperature - nuclei repel one another unless they have enough energy, approximately 100 million °C
|
|
|
One problem with developing nuclear fusion
|
2.) density - heavy hydrogen nuclei needed, 1 x 1014 /cm3
|
|
|
One problem with developing nuclear fusion
|
3.) time - must be sustained at a minimum of 10 atm at this density
|
