Answer:
Lavoisier; Newlands; Moseley
Explanation:
In 1789, Antoine Lavoisier grouped the elements into gases, nonmetals, metals, and earths.
In 1865, John Newlands developed the Law of Octaves. He stated that "any given element will exhibit analogous behaviour to the eighth element following it in the table."
In 1914, Henry Moseley found a correlation between the X-ray wavelength of an element and its atomic number. He was then able to restructure the periodic table according to atomic numbers.
Answer:
Following are the solution to the given points:
Explanation:
In point a, the answer is only ions because of 
has a strong electrolyte.
In point b, the answer is the only molecules because of ethanol 
, it has a nonelectrolyte.
In point c, the answer is the few ions because of hydrocyanic acid HCN, which has a weak electrolyte.
Answer : The partial pressure of 
and 
are, 84 torr and 778 torr respectively.
Explanation : Given,
Mass of = 15.0 g
Mass of = 22.6 g
Molar mass of = 197.4 g/mole
Molar mass of = 32 g/mole
First we have to calculate the moles of and .
and,
Now we have to calculate the mole fraction of and .
and,
Now we have to partial pressure of and .
According to the Raoult's law,
where,
= partial pressure of gas
= total pressure of gas
= mole fraction of gas
and,
Therefore, the partial pressure of and are, 84 torr and 778 torr respectively.
Answer:
B. Charges ( a slight positive charge on one end, and a slight negative charge on the other).
