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Where Q represents the quantity remaining after tyears and kis the decay

constant 0.00043. How long will take for 500g of radium to decay to 5g?

User Mikedugan
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Final answer:

The decay of iodine-131 can be calculated using an exponential decay equation and the decay constant. By rearranging this equation, we can solve for the time it takes for 90% of the substance to decay, given an initial concentration and a decay constant of 0.138 d−¹.

Step-by-step explanation:

Understanding the decay of radioisotopes requires the use of exponential decay equations and half-life concepts. The decay of radioactive material is an exponential process, which means that the amount of a radioactive substance decreases by a fixed percentage over equal time periods. The half-life is the amount of time it takes for half of the original substance to decay. This is expressed mathematically in a decay equation using the decay constant (k).

For iodine-131, with a given decay constant of 0.138 d−¹, to calculate how long it will take for 90% to decay, we would use the equation:

amount remaining = initial amount × e−kt

If we start with a 0.500 M solution, we want to find the time when the solution is reduced to 0.050 M (10% remaining). By rearranging the decay equation and solving for t, we can find the number of days it will take for this level of decay to occur.

User Nixda
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