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Half-Life
Half-life
The half-life of a substance is the time it takes for half of the atoms of that substance to decay.
Formula for half-life:
t = ln(2) / ฮป
where:
- t is the half-life
- ln is the natural logarithm
- ฮป is the decay constant
Explanation:
- The half-life is a constant for a particular substance.
- It is a measure of how quickly the substance decays.
- The half-life determines the rate of decay.
- After one half-life, half of the atoms of the substance will have decayed.
- After two half-lives, half of the remaining atoms will have decayed.
- After three half-lives, half of the remaining atoms will have decayed.
Examples:
- The half-life of carbon-14 is 5,730 years. This means that half of the carbon-14 atoms in a sample will decay to carbon-12 in 5,730 years.
- The half-life of iodine-131 is 8 days. This means that half of the iodine-131 atoms in a sample will decay to iodine-127 in 8 days.
Applications:
- Half-life is used to determine the decay constant of a substance.
- It is used to calculate the decay time of a substance.
- It is used to measure the half-lives of various substances.
Additional Notes:
- The half-life is a logarithmic quantity, meaning that it is measured in units of time that are multiples of the previous time interval.
- The half-life is a constant for a particular substance at a given temperature.
- The half-life can vary for different substances.
- The half-life is an important concept in many fields of science, including chemistry, physics, and biology.