Answer:
The isotope with the greatest number of protons is:
- <u>option D: Pu-239, with 94 protons</u>
Explanation:
The number of <em>protons</em> is the atomic number and is a unique number for each type of element.
You can tell the number of protons searching the element in a periodic table and reading its atomic number.
Thus, this is how you tell the number of protons or each isotope
Sample Chemical symbol Element atomic number # of protons
A Pa-238 Pa protactinium 91 91
B U-240 U uranium 92 92
C Np-238 Np neptunium 93 93
D Pu-239 Pu plutonium 94 94
Energy can be conserved by efficient energy use.
Answer: Option A
<u>Explanation:</u>
Energy can be transferred from one form to another, but it cannot be destroyed or created. So it can be conserved if efficiently used. Thus efficient usage of energy lead to conservation of energy. Due to conservation of energy, the forces can be renewable and non-renewable.
So, we should know how the input energy can be completely converted to another form of energy leading to efficient usage of energy without any loss. As if there is no loss, input energy will be equal to output energy leading to 100% efficiency.
True because certain fabric will catch on fire
Answer:
ΔS = -661.0J/mol is the entropy change for the system
ΔS = -842J/mol.K is the entropy change for the surroundings
Explanation:
From the relationship between ΔG, T, ΔH and ΔS,
Mathematically, ΔG = ΔH - TΔS
TΔS = ΔH - ΔS
ΔS = ΔH - ΔS / T
but ΔG = -54 kJ/mol, ΔH = -251 kJ/mol and T = 25 °C (298 K)
plugging into the equation,
ΔS = -251 kJ/mol - ( -54 kJ/mol) / 298
ΔS = -0.6610KJ/mol or in J.mol
ΔS = -661.0J/mol is the entropy change for the system
- For entropy change for the surroundings = ΔS = ΔH/T
- ΔS = -0.84KJ/mol.K or -842J/mol.K is the entropy change for the surroundings
Answer:
87.15%
Explanation:
To find percent yield, we can use this simple equation
Where "Actual" is the amount in grams actually collected from the reaction, and "Theoretical" is, well, the theoretical amount that should have been produced.
They give us these values, so to find the percent yield, just plug the numbers in.
So, the percent yield is 87.15%
An easy trick to remember how to do this is just to divide the smaller number by the bigger number and move the decimal back two places. If you have a percent yield greater than 100%, something is wrong in the reaction.
