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Half-Life

Ankit0

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.

FAQs

  1. What does half-life mean?

    Half-life refers to the time it takes for half of a substance, like a drug or a radioactive material, to decay or be eliminated.

  2. What does it mean if a drug has a half-life of 4 hours?

    If a drug has a half-life of 4 hours, it means that 50% of the drug will be eliminated from the body in 4 hours, and the remaining half will continue to decrease by half every 4 hours.

  3. Why is the half-life of a drug important?

    The half-life of a drug is important because it helps determine how often a drug should be taken to maintain its effectiveness and avoid side effects.

  4. What is half-life in nuclear physics?

    In nuclear physics, half-life is the time it takes for half of the atoms in a radioactive substance to decay into a more stable form, releasing radiation in the process.

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