Answer:
Explanation:
Two important formulas in radioactive decay are
1. Calculate the decay constant k
2. Calculate the time
Answer:
C) 295 kJ/mol (average of the values given)
Explanation:
We can use Hess' Law to calculate the energy of formation of the C-Cl bond:
C-C → 2C ΔH = -347 kJ/mol
Cl-Cl → 2Cl ΔH = -243 kJ/mol
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C + Cl → C-Cl ΔH = (-347/2)+(-243/2)
ΔH = -295 kJ/mol
Answer:
What does ppm mean? This is an abbreviation for "parts per million" and it also can be expressed as milligrams per liter (mg/L). This measurement is the mass of a chemical or contaminate per unit volume of water. Seeing ppm or mg/L on a lab report means the same thing.
that is all i have to say.
First off there are some issues in your questions but I can still help in answering this type of problem. First, there is no Sr-20. The 4 abundant form includes Sr-84, Sr-88, Sr-87, Sr-86, Sr-84.
More importantly, the half life of strontium must be given.
For demonstration sake, let us assume Sr-85 is the isotope. It has a half-life of 64.853 days and I'm assuming the units of 87.3 is in days.
A/Ao = e^-(ln2/t)T
where A- final amount Ao -initial amount t- halflife T-total time elapsed
% = <span>e^-(ln2/64.853)(87.3) = 0.3933 or 39.33%
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