A. I think sorry if it’s wrong
It would be the water based carbon cycle
Answer: Barium is +2, Fluorine is -1
Explanation:
The charge of barium is +2, and the charge of fluorine is -1. You can determine this from the periodic table groups.
The formula for barium fluoride is thus BaF2.
Answer:
Hydrogen ions
Explanation: acids will produce hydrogen ions, I asked my teacher. Please tell me if we are wrong.
Answer: The mass percentage of 
is 5.86%
Explanation:
To calculate the mass percentage of in the sample it is necessary to know the mass of the solute ( in this case), and the mass of the solution (pesticide sample, whose mass is explicit in the letter of the problem).
To calculate the mass of the solute, we must take the mass of the 
precipitate. We can establish a relation between the mass of and using the stoichiometry of the compounds:
Since for every mole of Tl in there are two moles of Tl in , we have:
Using the molar mass of we have:
Finally, we can use the mass percentage formula:
