Answer:

Explanation:
Hello,
In this case, we need to remember that for the required time for a radioactive nuclide as radium-226 to decrease to one half its initial amount we are talking about its half-life. Furthermore, the amount of remaining radioactive material as a function of the half-lives is computed as follows:

Therefore, for an initial amount of 100 mg with a half-life of 1590 years, after 1000 years, we have:

Best regards.
The heat required to raise the temperature to a specific temperature change of a sample is related to the specific heat capacity of the substance. In this case, the heat can be calculated through mCpΔT = 350 g * 0.39 J/g C *25 C. This is equal to 3412. 5 Joules. Closest answer is C.
The atomic mass on the periodic table represents the sum of number of protons and number of neutrons.
Atomic mass = Number of protons + number of neutrons
Hope this helps!
Answer:
Cost to supply enough vanillin is 
Explanation:
Threshold limit of vanillin in air is
per litre means there should be
of vanillin in 1L of air to detect aroma of vanillin.

So, 
So amount of vanillin should be present to detect = 
As cost of 50 g vanillin is
therefore cost of
vanillin = 
I think that it's d) F- but I'm not sure.