Evidence could be gathered in the future that contradicts original theories. <span>Phenomena cannot be proven by conclusive evidence in science because, as of now, the evidence isn't conclusive. It is speculation. Just as a phenomena cannot be proven, it also cannot be disproven. </span>
<span>Well it depends on percentage by what, but I'll just assume that it's percentage by mass.
For this, we look at the atomic masses of the elements present in the compound.
Cu has an atomic mass of 63.546 amu
Fe has 55.845 amu
and S has 36.065 amu
Since there are 2 molecules of Sulfur for each one of Cu and Fe, we'll multiply the Sulfur atomic weight by 2 to obtain 72.13 amu
So we have not established the mass of the compound in amus
63.546 + 55.845 + 72.13 = 191.521
That is the atomic mass of Chalcopyrite. and Iron's atomic mass is 55.845
So to get the percentage, or fraction of iron, we take 55.845 / 191.521
Which comes out to 29.15% by mass
Mass of the sample is not needed for this calculation, but since the question mentions it I would go ahead and check if the question isn't also asking for the mass of Iron in the sample as well, in which case you just find the 29.15% of 67.7g</span>
Group 7a would have an ion charge of -1 because it has 7 valence electrons and it wants to gain one more electron(which is negative) to have a full shell of 8
Answer:
So the molar mass of C4,H10 is
58.12g mole -1
The reactants are the substances on the left side, which react and give the products on the right side.
The reactants are Fe and O.
The product is Fe2O3.
The arrow to the right means that the reaction is going in only one direction — the only reaction happening at the moment is that Fe and O are making Fe2O3.
(s) means the substance is in the solid state, and (g) means in a gaseous state (or the substance is a gas in that reaction).
