true and false - 15
The nuclear radiation is also classified as „ionizing radiation“ because it can ionize atoms.
T
For each number of protonsin the nucleus there is a constant number of neutrons for maximum stability of the nucleus.
T
.The term „radioactive“ comes from „active like uranium“.
F
Alpha radiation is composed of two protons and three neutrons; it is a nucleus of the element helium.
F
Gamma radiation is distinguished from ß-rays only by the fact that it comes from the nucleus.
F
The enormous energy yield from mass conversion can be calculated by the Einstein equation.
T
A nucleus which emits a particle is transformed into a nucleus of a different chemical element.
T
The positron is the antiparticle of the proton.
F
The „biologic half-life“ is defined as the time taken to reduce the activity of radioisotopes to one-half by elimination processes.
T
Artificially produced radioisotopes are used for diagnostic purposes because of their comparitively short half-lives and the ease of introduction into living organisms.
T
X-rays or gamma rays may give all their energy to an electron in ejecting it from a molecule or they may give only a fraction of their energy to the electron and then „scatter“ the remainder off in the form of a lower frequency photon.
T
The roentgen is used for x-ray equipment calibration.
T
The rem is a unit that measure the radiation dose in terms of its biological effects.
T
Normal tissues recover slower and less completely from radiation effects than cancerous tissues.
F
A way to improve the therapeutic ratio for particle radiotherapy is to inject radium into a tumor and illuminate with low-energy neutrons.
F
The radiation exposure for diagnostic purposes is a thousand times less than in radiotherapy.
F
It is possible to release energy by nuclear fusion, the splitting the nuclei of heavy elements such as uranium into two or more lighter nuclei.
F
Intermediate-mass nuclei have the greatest binding energy or the minimum mass per nuclear particle.
T
All current nuclear power sources function on the basis of the nuclear fusion process.
F
For a given mass of fuel, the nuclear fusion process produces more energy than the nuclear fission process.
T
Rutherford carried out experiments to study the scattering of alpha particles by thin metal foils.
T
Alpha radiation is suitable for radiation therapy.
F
The radioactive nuclei can be introduced into any chemical compound.
T
Positron emission only occurs in artificially produced isotopes.
T
The number of nuclei of the original radioactive species increases with time.
F
Alpha radiation has a very short depth of penetration (r<0.01mm) inside the body.
F (R<0.1)
Radioisotope doses are typically measured in curie which is equivalent in activity to one gram of radium.
T
For a given radioisotope, the maximum total radiation in the body will arise if both the physical and biologic half-lives are short.
F
The radioactive decay rates are independent of temperature and matter state.
T
The curie is the unit for the activity of a given radioactive sample.
T