The postulate of Dalton's atomic theory which is a result of the law of conservation of mass is: Atoms are indivisible particles, which can neither be created nor destroyed in a chemical reaction.
Answer:
Explanation:
I’m 99.9% sure that it’s an element because it can’t be broken down any more than it already is.
The answer to your question is units and values
Answer:

Explanation:
The empirical formula is the simplest whole-number ratio of the elements in a compound to one another. To find the empirical formula given a molecular formula, divide all the subscripts by their greatest common factor.
3, 12, and 6 can all be divided by 3, which makes the empirical formula 
First equation:
molarity=
no.of moles of solute (Na2S)/volume of solution
0.300/1.75 = 0.171
second equation:
same law
but in volume it is milliliter so you have to convert it by multiplying it with 10^-3
(10 power -3)
to understand it clearly
see this
http://imgur.com/xTS35QM