Answer:
447.58 J
Explanation:
The change in internal energy is the difference between the heat absorbed and the work done due to gas expansion. The following variables are given in the problem:
Change in volume = ΔV = 2.0 L
External pressure = P = 0.93 atm
Work done due to gas expansion = W = P*ΔV = 2*0.93 = 1.86 L-atm
We can convert the work done from L-atm to J by using the conversion unit given in the question: 1 L-atm = 101.3 J. Thus:
Work done = 1.86*101.3 = 188.418 J
Change in Internal energy (ΔU) = heat absorbed (Q) - work done (W)
The heat absorbed is equivalent to 636 J. thus, the internal energy is:
ΔU = 636 - 188.418 = 447.58 J
Answer:
C. The lowest-energy electron configuration of an atom has the maximum number of unpaired electrons, all of which have the same spin, in degenerate orbitals.
Explanation:
The Hund's rule is used to place the electrons in the orbitals is it states that:
1. Every orbital in a sublevel is singly occupied before any orbital is doubly occupied;
2. All of the electrons in singly occupied orbitals have the same spin.
So, the electrons first seek to fill the orbitals with the same energy (degenerate orbitals) before paring with electrons in a half-filled orbital. Orbitals doubly occupied have greater energy, so the lowest-energy electron configuration of an atom has the maximum number of unpaired electrons, and for the second statement, they have the same spin.
The other alternatives are correct, but they're not observed by the Hund's rule.
<span>C) <u>Colloids</u></span><span>
Colloids have small non-dissolved particles that flow around in the mixture. These particles do not settle over time. When a light is shined on colloids the scattering characteristic of the Tyndall effect are visable.</span>