Answer:
The metal strip on the left has a lower activity than the one on the right.
(Took the exam)
Answer:
5:22 am
Explanation:
The gas X decays following a first-order reaction.
The half-life (
) is 25 min. We can find the rate constant (k) using the following expression.
![k = \frac{ln2}{t_{1/2}} =\frac{ln2}{25min} = 0.028 min^{-1}](https://tex.z-dn.net/?f=k%20%3D%20%5Cfrac%7Bln2%7D%7Bt_%7B1%2F2%7D%7D%20%3D%5Cfrac%7Bln2%7D%7B25min%7D%20%3D%200.028%20min%5E%7B-1%7D)
We can find the concentration of X at a certain time (
) using the following expression.
![[X] = [X]_0 \times e^{-k \times t}](https://tex.z-dn.net/?f=%5BX%5D%20%3D%20%5BX%5D_0%20%5Ctimes%20e%5E%7B-k%20%5Ctimes%20t%7D)
where,
: initial concentration of X
t: time elapsed
![\frac{[X]}{[X]_0}= e^{-k \times t}\\\frac{1/10[X]_0}{[X]_0}= e^{-0.028min^{-1} \times t}\\t=82min](https://tex.z-dn.net/?f=%5Cfrac%7B%5BX%5D%7D%7B%5BX%5D_0%7D%3D%20e%5E%7B-k%20%20%5Ctimes%20t%7D%5C%5C%5Cfrac%7B1%2F10%5BX%5D_0%7D%7B%5BX%5D_0%7D%3D%20e%5E%7B-0.028min%5E%7B-1%7D%20%20%5Ctimes%20t%7D%5C%5Ct%3D82min)
The earliest time Professor Utonium can come back to do experiments in the lab is:
4:00 + 82 = 5:22 am
Answer:
J.J. Thomson
Explanation:
According to my book and wiki, Historically, the mass of the electron was determined directly from combining two measurements. The mass-to-charge ratio of the electron was first estimated by Arthur Schuster in 1890 by measuring the deflection of "cathode rays" due to a known magnetic field in a cathode ray tube. It was seven years later that J. J.
Please correct me if I'm wrong.
Explanation: When Iron(III) nitrate reacts with lithium hydroxide in their aqueous state produces Iron (III) hydroxide and Lithium nitrate in their aqueous state.
Balancing a chemical reaction: In a chemical equation, the total number of atoms and total charge on every element remains same on both reactant and product side.
Balanced Chemical reaction will be:
![Fe(NO_3)_3(aq.)+3LiOH(aq.)\rightarrow Fe(OH)_3(aq.)+3LiNO_3(aq.)](https://tex.z-dn.net/?f=Fe%28NO_3%29_3%28aq.%29%2B3LiOH%28aq.%29%5Crightarrow%20Fe%28OH%29_3%28aq.%29%2B3LiNO_3%28aq.%29)
As the metal rusts it expands increasing its mass therefore increasing the weight.