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An isotope of a chemical element is an atom that has the same number of protons (this also means this atom has the same atomic number) and electrons, but has a different numbers on neutrons. The isotope is radioactive if it has too many neutrons in the nucleus and because of this the isotope is unstable.
The half-life of a radioactive isotope is a time period. When the isotope is at the end of the period it's weight will be the half of the starter weight.
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MaxineShelf life refers to the time a product can be stored before it is no longer safe for consumption or use. Half life, on the other hand, is the time it takes for half of a substance to decay or lose its potency through a process such as radioactive decay or chemical breakdown.
The difference between count rate and activity of a radioactive sample is simply geometry - geometry as in the ratio of disintegrations versus observed counts.
It is true that activity is proportional to activity. One curie is defined as 3.7x1010 disintegrations per second (DPS), or one microcurie is more commonly defined as 2.2x106 disintegrations per minute (DPM). The problem is that not all of the disintegrations get counted. After all, the detector does not completely surround the source and, even if it did, still not all of the disintegrations will be counted.
During calibration, a known activity is presented to the detector in a known geometry, and the count rate is measured. Lets say that 0.01 microcurie yields 1x104 counts per minute. We would say, then, that the instrument's absolute efficiency is 0.45%, which is the ratio of 1x104 over 2.2x106. If you then measured an unknown activity and got 5x103 counts per minute, you could reasonable assume that the sample was 0.005 microcuries.
These number are all examples, "picked out of the air", to illustrate the principle. Actual detector design and geometry is a complex science and other factors, such as emergy absorbtion, pulse nullification, and linear vs avalanche mode, just to name a few, factor into the proper design and calibration of a detector.
- Shelf life: Time that something (e.g. food, batteries) can stay good in storage, unused (aka on the shelf). This is a rough estimate that depends on various conditions (e.g. temperature, humidity).
- Half life: Time that something unstable (e.g. radioisotope) takes to decay to half its previous quantity. This is a physical constant for every item having this property.
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What is the difference between serum half life and elimination half life?
Serum half-life refers to the time it takes for the drug concentration in the bloodstream to decrease by 50%. Elimination half-life refers to the time it takes for the drug concentration in the body to decrease by 50% due to elimination processes such as metabolism and excretion. Serum half-life is more focused on drug levels in the blood, while elimination half-life reflects the overall removal of the drug from the body.
Does DNA have a shelf life?
DNA itself does not have a shelf life as long as it is stored properly and protected from damage. However, its ability to be sequenced or analyzed can degrade over time due to environmental factors or improper storage conditions.
How the rate of radioactivity of uranium 238 can be speeded up by?
The half life is practically a constant for each isotope; sometimes the half life depend on the chemical compound but the difference is very small.
What is technetium 99 half life?
The half life of technetium-99 is 2,111.10e+5 years.Avoid a confusion between Tc-99 and Tc-99m.
What is the shelf life of monomers?
The shelf life of monomers can vary depending on the specific type of monomer and storage conditions. Generally, monomers have a shelf life of around 1-2 years if stored properly in a cool, dark place away from heat and moisture to prevent polymerization. It is important to check the manufacturer's guidelines for specific shelf life information.
