It's because proteins are very small and hard to see.
Answer is (4).<span>
<em>
</em></span>
<span><em>Explanation:</em>
</span><span>
<span>The given mixture contains an </span>insoluble solid<span> <span>and an </span></span>aqueous solution of salt. <span>The insoluble solid is </span>sand. <span>
First </span><span>we have to separate </span>insoluble solid. <span>Sand can be separated by doing </span>filtration. When we filter the mixture sand can be seen as the residue on the filter paper.
<span>After filtering the mixture, we should collect the </span>filtrate. <span>Filtrate is the </span>salt solution. <span>By doing </span>evaporation <span>we can get the </span>solid salt. <span>
First </span>and second choices are wrong <span>because </span>after evaporating water filtration
cannot be done and salt and sand will be mixed together.<span>
Salt cannot be
filtered out because the salt is soluble and it is <span>in
aqueous medium. Hence, third choice is wrong</span></span></span>
Answer:
I think the answer is 368.544 centigrams
Explanation:
I hope I helped
Answer:
8.354 nanometers
Explanation:
To treat a diffusive process in function of time and distance we need to solve 2nd Ficks Law. This a partial differential equation, with certain condition the solution looks like this:

Where Cs is the concentration in the surface of the solid
Cx is the concentration at certain deep X
Co is the initial concentration of solute in the solid
and erf is the error function
Then we solve right side,

And we need to look up the inverse error function of 0.001964 resulting in: 0.00174055
Then we solve for x:

Answer:
Percentage mass of copper in the sample = 32%
Explanation:
Equation of the reaction producing Cu(NO₃) is given below:
Cu(s)+ 4HNO₃(aq) ---> Cu(NO₃)(aq) + 2NO₂(g) + 2H₂O(l)
From the equation of reaction, 1 mole of Cu(NO₃) is produced from 1 mole of copper. Therefore, 0.010 moles of Cu(NO₃) will be produced from 0.010 mole of copper.
Molar mass of copper = 64 g/mol
mass of copper = number of moles * molar mass
mass of copper = 0.01 mol * 64 g/mol = 0.64 g
Percentage by mass of copper in the 2.00 g sample = (0.64/2.00) * 100%
Percentage mass of copper in the sample = 32%