Answer : The correct option is, mixture
Explanation :
Mixture : It is defined as the substance that is made by the combination of two or more different components.
Pure substance : It is defined as a substance that is made by the combination of only one type of atom or only one type of molecule.
Compound : It is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Element : It is a pure substance which is composed of atoms of similar elements.
According to the definition of mixture, black powder is a mixture because it is made by the combination of red particles that float to the top, black particles that sink to the bottom and a green color liquid.
Hence, the correct option is, mixture
Answer:
The molar concentration would have to be 0,81 M.
Explanation:
The osmotic pressure equation is:

where:
: osmotic pressure [atm]
M: molar concentration [M]
R: gas constant 0,08205 [atm.L/mol.°K]
T: absolute temperature [°K]
To solve the problem, we just clear M from the osmotic pressure equation and then replace our data using the appropiate units. Clearing the variable M we have:

We have to use temperature as absolute temperature (in kelvins), T=29+273=302 °K. Now we can replace our values in the equation:

As we can see, all units will be simplified and we'll have the molar concentration in mol/L.

Answer:
During the electrolysis, hydrogen and chloride ions are removed from solution whereas sodium and hydroxide ions are left behind in solution. This means that sodium hydroxide is also formed during the electrolysis of sodium chloride solution.
Sulfur is the answer!
others are metalloid!