Answer:
8. 2.75·10^-4 s^-1
9. No, too much of the carbon-14 would have decayed for radiation to be detected.
Explanation:
8. The half-life of 42 minutes is 2520 seconds, so you have ...
1/2 = e^(-λt) = e^(-(2520 s)λ)
ln(1/2) = -(2520 s)λ
-ln(1/2)/(2520 s) = λ ≈ 2.75×10^-4 s^-1
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9. Reference material on carbon-14 dating suggests the method is not useful for time periods greater than about 50,000 years. The half-life of C-14 is about 5730 years, so at 65 million years, about ...
6.5·10^7/5.73·10^3 ≈ 11344
half-lives will have passed. Whatever carbon 14 may have existed at the time will have decayed completely to nothing after that many half-lives.
Answer: Option (C) is the correct answer.
Explanation:
As we know that metals are able to conduct electricity so, when a negatively charges rod is kept closer to the left sphere then electrons will enter the sphere.
Since, like charges repel each other. Hence, some of the negative changes from the rod will repel the negative charges of left sphere.
As both left and right spheres are touching each other so, the electrons will move towards the right sphere. As a result, there will be too many electrons (negative charge) present on the right sphere and very less electrons present in the left sphere.
Thus, we can conclude that the statement right sphere is negatively charged, another is charged positively, is true.
Answer:
True
Explanation:
The products of a reaction are determined by the type of chemical reaction that are taking place. This is very true.
In chemical reactions, bonds are broken and atoms re-arranged to form new products.
- By virtue of this, we can predict and know the kind of permissible combinations that can take place.
- There are different kinds of chemical reaction.
- They are synthesis, decomposition, single displacement, double displacement reactions e.t.c
- Knowing these reactions gives insight into the likely products we can obtain.
Answer:
Not 500 points I got 18 but thx
Explanation:
