Half Life
Half-life is how long it will take for a substance to decay. This measurement is applied to things that may decay over a certain amount of time, meaning that the rate of decay is directly proportional to the amount of the substance. Half-life varies widely, it can be a few seconds or millions of years, depending on substance.
Every substance has a half-life until it reaches very small amounts, even though the rate of decay slows over time. Imagine an element has a half-life of five minutes, for example. If we start out with 20 ounces of a substance, five minutes later we will have 10 ounces remaining, and in another five minutes only 5 ounces remaining. The rate of decay has slowed from 2 ounces per minute to 1 ounce per minute, but the half-life is constant at five minutes.
Example of Half Life: How much of a 150 gram sample of 32Ag is left after 10 days, what is the half life at 2.5 days?
For days you would start with 10, then divide by 2 until you get to 2.5 days. Then you start 150 until it matches with the grams had at 2.5 days
10 150 5 75 2.5 37.5
So the half life of 32Ag at 2.5 days is 37.5
Every substance has a half-life until it reaches very small amounts, even though the rate of decay slows over time. Imagine an element has a half-life of five minutes, for example. If we start out with 20 ounces of a substance, five minutes later we will have 10 ounces remaining, and in another five minutes only 5 ounces remaining. The rate of decay has slowed from 2 ounces per minute to 1 ounce per minute, but the half-life is constant at five minutes.
Example of Half Life: How much of a 150 gram sample of 32Ag is left after 10 days, what is the half life at 2.5 days?
For days you would start with 10, then divide by 2 until you get to 2.5 days. Then you start 150 until it matches with the grams had at 2.5 days
10 150 5 75 2.5 37.5
So the half life of 32Ag at 2.5 days is 37.5