Because they have a full outer shell and they are both noble gases...Because the outer shell has attained stable electronics configuration of octate rule this it is with noble gas as helium.
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Density is the ratio of mass to the volume.
The mathematical expression is given as:

Now, density of isooctane = 
Volume = 
Since, 1 gallon = 3.78 L
So, 3.8 gal = 
= 
As, 1 L = 1000 mL
Therefore,
= 
Volume in mL = 
Put the values,


= 
Hence, mass of 3.8 gal of the gasoline is
.
ΔG° at 450. K is -198.86kJ/mol
The following is the relationship between ΔG°, ΔH, and ΔS°:
ΔH-T ΔS = ΔG
where ΔG represents the common Gibbs free energy.
the enthalpy change, ΔH
The temperature in kelvin is T.
Entropy change is ΔS.
ΔG° = -206 kJ/mol
ΔH° equals -220 kJ/mol
T = 298 K
Using the formula, we obtain:
-220kJ/mol -T ΔS° = -206kJ/mol
220 kJ/mol +206 kJ/mol =T ΔS°.
-T ΔS = 14 kJ/mol
for ΔS-14/298
ΔS=0.047 kJ/mol.K
450K for the temperature Completing a formula with values
ΔG° = (450K)(-0.047kJ/mol)-220kJ/mol
ΔG° = -220 kJ/mol + 21.14 kJ/mol.
ΔG°=198.86 kJ/mol
Learn more about ΔG° here:
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It is important to take note of th temperature in determining the density of a substance because this will set as a basis and will likely be a variable in the experiment because this will also contribute on the effects of the experiment and a basis of how the experiment has turned to be that way.
<span>The righ answer is the option A. They are made up of two or more pure substances that are not chemically bonded. A classicall expample ot heterogeneous mixtures are sugar and salt. Sugar is a pure substance, salt is also a pure substance, when you mixe them you form mixture where salt is still salt and sugar is still sugar, that is what "they are not chemically bonded" means. So you can separate them by physical media. </span>