You have 480 grams of a radioactive kind of tin. If its half-life is 10 days, how much will be left after 30 days?
After 10 days you have half left
After 20 days that's half of the half again = a quarter
After 30 days that's half of a quarter = an eighth
480 / 8 = 60 grams
Equation :
N( t ) = N( 0 ) * ( 1 / 2 ) ^ [ t / t( 1 / 2) ]
In this case :
N ( 30 ) = 480 * ( 1 / 2 ) ^ ( 30 / 10 )
N ( 30 ) = 480 * ( 1 / 2 ) ^ 3
N ( 30 ) = 480 * 1 / 8 = 60 grams
Also you can in google type:
half-life equation
and click : en.wikipedia
Suppose that a certain radioactive substance has a half-life of 20 years. If there are presently 2400 milligrams of the substance, how much, to the nearest milligram, will remain after 70 years?
To find out how much radioactive tin will be left after 30 days, 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 to decay or transform into another element.
In this case, the half-life of the radioactive tin is given as 10 days. This means that after 10 days, half of the initial amount will remain, and after another 10 days, half of that amount will remain, and so on.
To determine how much will be left after 30 days, we can divide the total time (30 days) by the half-life (10 days) to find out how many cycles of decay have occurred. In this case, 30 days divided by 10 days equals 3 cycles.
Now, let's calculate the amount of tin left after each cycle:
1st cycle: After 10 days, half of the initial amount will be left.
Remaining amount = 480 grams / 2 = 240 grams
2nd cycle: After another 10 days (20 days in total), half of the remaining amount will be left.
Remaining amount = 240 grams / 2 = 120 grams
3rd cycle: After 30 days (3 cycles of 10 days each), half of the remaining amount will be left.
Remaining amount = 120 grams / 2 = 60 grams
Therefore, after 30 days, there will be 60 grams of the radioactive tin left.