Answer:
Mass of original sample = 100 g
Explanation:
Half life of cesium-137 = 30.17 years
Where, k is rate constant
So,
The rate constant, k = 0.02297 year⁻¹
Time = 90.6 years
Using integrated rate law for first order kinetics as:
![[A_t]=[A_0]e^{-kt}](https://tex.z-dn.net/?f=%5BA_t%5D%3D%5BA_0%5De%5E%7B-kt%7D)
Where,
![[A_t]](https://tex.z-dn.net/?f=%5BA_t%5D)
is the concentration at time t
![[A_0]](https://tex.z-dn.net/?f=%5BA_0%5D)
is the initial concentration
Initial concentration = ?
Final concentration = 12.5 grams
Applying in the above equation, we get that:-
![12.5\ g=[A_0]e^{-0.02297\times 90.6}](https://tex.z-dn.net/?f=12.5%5C%20g%3D%5BA_0%5De%5E%7B-0.02297%5Ctimes%2090.6%7D)
![[A_0]=\frac{12.5}{e^{-0.02297\times 90.6}}\ g=100\ g](https://tex.z-dn.net/?f=%5BA_0%5D%3D%5Cfrac%7B12.5%7D%7Be%5E%7B-0.02297%5Ctimes%2090.6%7D%7D%5C%20g%3D100%5C%20g)
<u>Mass of original sample = 100 g</u>
Answer:without predators, to keep prey from producing too many and over eating, the ecosystem suffers as there isn’t enough for the prey themselves to eat.
Explanation:
Answer:
neutralization reaction! Aka: option C!
HOPE THIS HELPS! :)
Explanation:
Answer:
Evaporation
Explanation:
Evaporation is the certain process that requires water to gain heat energy from the environment.
Answer:
V = 0.356 L
Explanation:
In this case, we need to use the following expression:
M = n/V (1)
Where:
M: molarity of solution (mol/L or M)
n: moles of solute (moles)
V: Volume of solution (Liters)
From these expression, we can solve for V:
V = n/M (2)
Now, replacing the given data we can solve V:
V = 8.9 / 25
V = 0.356 L
