A radio substance has a half-life of 10 years. What is its annual decay rate?
You are talking about a radioactive substance-- one that emits radiation-- NOT a radio.
The annual decay rate is what you multiply the number of radioactive atoms by to get the decay rate, k, in atoms per year.
See http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/halfli2.html
The decay rate is 0.693 divided by the half life, or 0.0693 yr^-1 in this case.
To determine the annual decay rate of a radioactive substance with a half-life of 10 years, we need to understand the concept of half-life.
The half-life of a substance is the time it takes for half of the initial amount of the substance to decay or transform into another element. In this case, the half-life is 10 years, meaning that after 10 years, half of the original substance will have decayed.
To find the annual decay rate, we can divide the half-life by the number of years.
Annual decay rate = Half-life / Number of years
In this case, the half-life is 10 years, and we want to find the annual decay rate. Assuming that the radio substance decays at a steady rate, we can divide 10 years by 1 year.
Annual decay rate = 10 years / 1 year = 10
Therefore, the annual decay rate of the radio substance with a half-life of 10 years is 10. This means that on average, 10% of the substance will decay each year.