Answer:
52.54 %
Explanation:
Half life = 29 years
Where, k is rate constant
So,
The rate constant, k = 0.023902 hour⁻¹
From 1964 to 1991:
Time = 27 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
So,
![\frac {[A_t]}{[A_0]}=e^{-0.023902\times 27}](https://tex.z-dn.net/?f=%5Cfrac%20%7B%5BA_t%5D%7D%7B%5BA_0%5D%7D%3De%5E%7B-0.023902%5Ctimes%2027%7D)
![\frac {[A_t]}{[A_0]}=0.5245](https://tex.z-dn.net/?f=%5Cfrac%20%7B%5BA_t%5D%7D%7B%5BA_0%5D%7D%3D0.5245)
<u>The strontium-90 remains in the bone = 52.54 %</u>
Answer:
The correct answer is in an exothermic reaction the energy of the product is less than the energy of the reactants.
Explanation:
Exothermic reaction is a type of reaction that generates heat.As a result in case of an exothermic reaction the energy of the reactant is more than the energy of the product.
That"s why the enthalpy change in an exothermic reaction is always positive .
Answer: C
Explanation:
The one closest to the atomic center, there is a single 1s orbital that can hold 2 electrons. At the next energy level, there are four orbitals.
The law of conservation of energy or first law of thermodynamics
Explanation:
From the context we can infer that Mr. Jones was describing the law of conservation of energy.
According to the law of conservation of energy:
"energy is not created nor destroyed by can be transformed from one form to another" .
The captured energy is a form of energy and it is change into other forms in the ecosystem.
Energy is initially captured in the ecosystem by plants.
learn more:
Laws of thermodynamics brainly.com/question/3564634
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