Answer:
Movements along faults can make it harder for geologists to determine the relative ages of rock layers.
Explanation:
The absolute age of a sample is its age in years. This method of determining absolute age is called radiometric dating, and it involves the decay, or breakdown, of radioactive elements. Using radiometric dating, scientists can determine the actual age of a rock.
Salt water is a homogeneous mixture or a solution.
Set this up as
10 = 40 (1/2)t/28
and solve for t in years.
10/40 = (1/2)t/28
log(0.25) = (t/28) log(0.5)
t = 28 log(0.25) / log(0.5) years = 56 years
Test the answer:
56 years = 2(28 years) = 2 half-lives, so the remaining amount should be 1/2 of 1/2 of the initial amount, i.e. 1/4 of the initial amount, and 10 mg = 1/4 of 40 mg.
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The ozone layer protects us from the harmful emission of rays directly to the environment. Absent this added layer of protection we humans will be susceptible to various forms of cancer due to over radiation and eye problems such as cataracts. It is estimated that 10% of the world's population will face the consequences of ozone depletion this year and these numbers were continue to rise as time progresses.
