<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>
It was loss of nutrients, I think
Explanation:
The quarry was dug up and vegetation started dying. The quarry was probably rich with nutrients
Please brainliest !! ❤️
In a chemical reaction, the difference between the potential energy of the products and the potential energy of the reactants is equal to the heat of the reaction<span>. This is, the net energy released or absorbed (change) during a chemical reaction is the sum of the potential energy of the products less the sum of the potential energy of the reactants.</span>
Your answer should be C.) +2. "All the elements in Group 2 have two electrons in their valence shells, giving them an oxidation state of +2."
Credits: https://chem.libretexts.org/Core/Inorganic_Chemistry/Descriptive_Chemistry/Elements_Organized_by_Blo...
Hopefully this has helped! :)
The answer would be KMnO4, please let me know if you would like me to explain how i got this
