Answer:
0.9715 Fraction of Pu-239 will be remain after 1000 years.
Explanation:
Where:
= decay constant
=concentration left after time t
= Half life of the sample
Half life of Pu-239 = 
[
![\lambda =\frac{0.693}{24,000 y}=2.8875\times 10^{-5} y^{-1]](https://tex.z-dn.net/?f=%5Clambda%20%3D%5Cfrac%7B0.693%7D%7B24%2C000%20y%7D%3D2.8875%5Ctimes%2010%5E%7B-5%7D%20y%5E%7B-1%5D)
Let us say amount present of Pu-239 today = 
A = ?
![A=x\times e^{-2.8875\times 10^{-5} y^{-1]\times 1000 y}](https://tex.z-dn.net/?f=A%3Dx%5Ctimes%20e%5E%7B-2.8875%5Ctimes%2010%5E%7B-5%7D%20y%5E%7B-1%5D%5Ctimes%201000%20y%7D)
0.9715 Fraction of Pu-239 will be remain after 1000 years.
The answer is D) wood decaying
Answer:
A reaction is non-spontaneous at any temperature when the Gibbs free energy > 0.
Explanation:
There is a state function, that determines if a reaction is sponaneous or non spontaneous:
ΔG = Gibbs free energy
A reaction is non spontaneous when it does require energy to produce that reaction. It will be spontaneous, when the reaction does not require energy to be occured.
The formula is: ΔG = ΔH - T.ΔS
ΔH → Enthalpy → Energy gained or realeased as heat.
ΔH < 0 → <em>Exothermic reaction. Spontaneity is favored
</em>
T → Temperature
ΔS → Entropy → Degree of disorder of a system.
When the system has a considered disorder ΔS > 0, disorder increases.
When the system is more ordered, ΔS < 0, disorder decreases.
The reaction will be non spontaneous if, the enthalpy is positive (endothermic reaction) and the ΔS < 0 (disorder decreases). It will not occur if we do not give energy.
ΔG < 0 → Spontaneous reaction
ΔG > 0 → Non spontaneous reaction
ΔG = 0 → System in equilibrium
2Na + H₂ = 2NaH (sodium-hydride).
Answer:
The plum pudding model of the atom agreed with the nuclear model
Explanation:
