Answer:
Step-by-step explanation:
As an example, iodine-131 is a radioisotope with a half-life of 8 days. It decays by beta particle emission into xenon-131. After eight days have passed, half of the atoms of any sample of iodine-131 will have decayed, and the sample will now be 50% iodine-131 and 50% xenon-131.
50 grams to 25 grams is one half-life. 25 grams to 12.5 grams is another half-life. So, for 50 grams to decay to 12.5 grams, two half-lives, which would take 36 days total, would need to pass. This means each half-life for element X is 18 days.
Answer:
Mass of A = 5760 grams
Step-by-step explanation:
Surface area is given, so we can set-up a similarity equation to solve for k, proportionality constant. Here, we will relate both of them through k^2, because they are 2 dimensional (area). Thus
Surface Area of A = k^2 * Surface Area of B
28 = k^2 * 40.32
k^2 = 28/40.32
k^2 = 25/36
k = Sqrt (25/36)
k = 5/6
Now, we want to find mass (1 dimensional quantity), thus we can say:
Mass of A = k * Mass of B
Mass of A = (5/6) * (6912)
Mass of A = 5760 grams
X^2
You subtract exponents when dividing exponents
Answer:
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Step-by-step explanation:
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