What is the decay constant of cesium 137?
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What is the decay constant of cesium 137?
Cs decays with a half-life of (30.05 ± 0.08) years [4] to either the 137Ba ground state, with emission of a β particle (Q = 1176 keV, 5.3\%), or to 137mBa (Q = 514 keV, 94.7\%) which rapidly (t1/2 = 2.552 min) decays to the 137Ba ground state with emission of a 661.7 keV γ photon.
What is a safe amount of cesium 137?
4 millirem per year
EPA, has established a Maximum Contaminant Level (MCL) of 4 millirem per year for beta particle and photon radioactivity from man-made radionuclides in drinking water.
How does cesium 137 atoms cause tissue damage?
A Cs-137 atom emits radiation in the form of medium energy gamma rays, and to a lesser extent, high-energy beta particles, which disrupt molecules in cells and deposits energy in tissues, causing damage.
What does it mean to say Caesium 137 has a half-life of 30 years?
1981). When we talk about radiocesium, we mean cesium-137. Stable cesium 133 (Cs-133) is the only naturally occurring isotope. It is found mainly in the mineral pollucite, containing up to 30\% Cs20….Caesium 137.
| Caesium 137 | |
|---|---|
| effective half-life human | approx. 69 – 109 days |
| Accumulation in | Muscle tissue |
What affects the decay constant?
The decay constant depends only on the particular radioactive nuclide and decay mechanism involved. It does not depend on the number of nuclei present or on any external conditions (such as temperature). It is not possible to combine decay constants in a simple way.
What factors affect the decay constant?
The decay constant, λ (lambda), is the “probability” that a particular nucleus will decay per unit time. The decay constant is unaffected by such factors as temperature, pressure, chemical form, and physical state (gas, liquid, or solid).
What negative health effects on the human body does caesium 137 produce?
External exposure to large amounts of Cs-137 can cause burns, acute radiation sickness, and even death. Exposure to Cs-137 can increase the risk for cancer because of exposure to high-energy gamma radiation.
What are the health effects of cesium 137?
What type of radiation does Caesium 137 emit?
Beta Particles Gamma Rays
Type of Radiation Emitted: Beta Particles. Gamma Rays.
What half-life means?
Half-life (symbol t1⁄2) is the time required for a quantity to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive.
What is meant by effective half-life?
The time required for the activity of a particular radioisotope deposited in a living organism, such as a human or an animal, to be reduced by 50 percent as a result of the combined action of radioactive decay and biological elimination.