I think the correct answer from the choices listed above is option B. When a substance changes from one phase to another, the average kinetic energy of the substance <span>changes since the molecules movements are changed as well. Hope this answers the question. Have a nice day.</span>
Answer:
When an electron absorbs energy, it will move up from a lower energy level to a higher energy level, called the "excited state" of the negatively-charged subatomic particle.
Explanation:
The given data is as follows.
Pressure (P) = 170 torr, mass of heptane (m) = 86.7 g
First, we will calculate the number of moles as follows.
No. of moles = 
= 
= 0.867 mol
Now, the number of moles of
are calculated as follows.
No. of moles = 
=
= 1.07
Therefore, mole fraction of heptane will be calculated as follows.
Mole fraction =
= 
= 
= 0.445
Now, we will calculate the partial pressure of heptane as follows.

=
= 75.65 torr
Thus, we can conclude that the partial pressure of heptane vapor above this solution is 75.65 torr.
Answer:
B. hydrogen
Explanation:
that's because hydrogen is an element.
The pressure in a sealed container means the volume of container is fixed
so we cannot change the volume of container hence gas
The other factors which can affect the pressure are
a) moles of gas : if we increase the moles of gas the pressure of gas will increase
b) Temperature: if we increase the pressure of gas the pressure of gas will increase due to increase in kinetic energy
So the following cannot increase pressure
a) decrease in moles of gas
b) decrease in temperature of gas