2K + Br2 ===> 2KBr
It's very ionic. The transfer of 2 electrons from K to Br2 is nearly as complete as it can be.
Answer:
The great confrontation between the two men occurred in 1686 when Newton published the first volume of his Principia and Hooke affirmed that it was he who had given him the notion that led him to the law of universal gravitation. Hooke demanded credit as the author of the idea but Newton denied it
Explanation:
The answer is: all true
<span>A. As the pressure of the gas increased, the volume of the gas decreased.
It is clear that if you compare the data on the left side. When the pressure increased the volume is decreased.
B. For all pairs of data of pressure and volume, P • V was appoximately the same.
The pressure is inversely related to the volume. You can take two data to prove it. Let use the first and second data
V * P= 1.03 * 50= 51.5
</span>V * P= <span>1.08 * 47.5= 51.3
C. For all pairs of data of pressure and volume, P • V mr001-1.jpg k for the same value k.
D. The regression equation was of the form V = kP–1 (which is the same as V = k/P).
The value of k can be expressed as k= P*V. If the equation is turned around, it could be expressed as V= k/P
The value of k is constant on different data, proved by the calculation on the second statement above. The value of k should be around 51.5
</span>
Answer:
Explanation:
The<em> half-life </em>time of a radiactive isotope (radioisotope) is a constant value, meaning that the amount of the radioisotope that decays will be (1/2) raised to the number of half-lives passed.
Naming A₀ the initial amount to the radioisotope, you can build this table to find the amount left.
Number of half-lives amount of radiosotope left
0 A₀
1 (1/2) × A₀
2 (1/2)×(1/2)×A₀ = (1/2)² × A₀
3 (1/2)³ ×A ₀
4 (1/2)⁴ × A₀
n (1/2)ⁿ × A₀
Now calculate the number of half-lives the strontium-90 sample has passed after 100 years:
- n = 100 years / 28.1 years ≈ 3.5587
Hence, the amount of strontium-90 is:
In percent, that is:
Rounding to two significant figures, that is 8.5%.
<u>Conclusion</u>: <em>The percent of strontium-90 left after 100 yeaers is 8.5% </em>(choice number 4).
