Answer:
B. 111 J
Explanation:
The change in internal energy is the sum of the heat absorbed and the work done on the system:
ΔU = Q + W
At constant pressure, work is:
W = P ΔV
Given:
P = 0.5 atm = 50662.5 Pa
ΔV = 4 L − 2L = 2 L = 0.002 m³
Plugging in:
W = (50662.5 Pa) (0.002 m³)
W = 101.325 J
Therefore:
ΔU = 10 J + 101.325 J
ΔU = 111.325 J
Rounded to three significant figures, the change in internal energy is 111 J.
There is no temperature at all shown below. Is that the same as Absolute Zero ?
Answer: It will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams
Explanation:
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Half life is represented by 

= rate constant
Given : Strontium-90 decreases in mass by one-half every 29 years , that is half life of Strontium-90 is 29 years.
As half life is independent of initial concentration, it will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams as the amount gets half.
The answer is: Electrons are shared in each pi bond. If the pi bonds flip back and forth between the adjacent p-orbitals on the two sides of an atom, the shared electrons in the p-orbitals can become delocalized.
Hope this help