Answer:
0.08 mL
Explanation:
The solution of the skin test has a concentration of 0.2% (w/v), which means that there are 0.2 g of the antigen per 100 mL of the solution. If a new solution will be done using it, then this solution will be diluted, and the mass of the antigen added must be the same in the volume taken and at the diluted solution.
The mass is the concentration (in g/mL) multiplied by the volume of the solution (in mL), so, if m is the mass, C the concentration, V the volume, 1 the initial solution, and 2 the diluted:
m1 = m2
C1*V1 = C2*V2
Where
C1 = 0.2 g/100 mL = 0.002 g/mL
V1 = ?
C2 = 0.04 mg/mL = 0.00004 g/mL
V2 = 4 mL
0.002*V1 = 0.00004*4
V1 = 0.08 mL
It is a physical separation.
Only chemical separation involves the changing of substances and their bondings, which usually involves the use of heat or electricity. Meanwhile, physical changes does not require breaking the bonds of substances or changing a substance to another, common examples of physical separations are such as filtration or distillation.
Since straining pasta from water does not require breaking the pasta or water to other substances, plus heat and electricity is not involved, therefore this is a type of physical separation.
Answer:
A.It lowers the melting point of alumina. B.It increases the electrical conductivity. ... Hint: The solution of alumina and cryolite during the electrolysis gives the aluminium at cathode and oxygen at anode. The alumina is a poor conductor of electricity and the fusion temperature of alumina is about 2000∘C.
Answer:
3) The People
Explanation:
Members Of Congress In Both Houses ( Democrats And Republicans ) Are Elected By Direct Popular Vote. Senators Are Elected Via A Statewide Vote ( The People All Around The World ) And Representatives Are Elected By Voters In Each Congressional District.
