Answer: -
2.5 moles of calcium atoms are in 2.5 moles of calcium carbonate CaCO₃
Explanation: -
In order to solve such types of problems, the first step would be to write the chemical formula of the compound.
The chemical formula of calcium carbonate = CaCO₃
The chemical symbol of Calcium is Ca.
From the formula of calcium carbonate we can see that
1 mole of CaCO₃ has 1 mole of Ca
2.5 mole of CaCO₃ has 
= 2.5 mol of Ca.
∴2.5 moles of calcium atoms are in 2.5 moles of calcium carbonate CaCO₃
Answer:
strontium oxide + hydrochloric acid (HCL) = strontium chloride
The answer is simulus check baby girl
CuCl2 is Dichloride Copper, or Copper II Chloride.
In this Molecule, there is 1 atom of Copper for every 2 atoms of Chlorine.
If you go to the periodic table, you'll see that copper has a mass of 63.5 amu, and the chlorine 35.45 amu.
Which mean that the mass of CuCl2 is 63.5 + 35.45*2 = 63.5 + 70.9 = 134.4 g/mol.
Then, you find the ration of the mass of each atom and multiply by 100.
Ratio of Copper:

and you get about 47.2%
Ration of chlorice (Cl2):

and you get about 52.8%.
So, the percent composition of CuCl2 is 47.2% of Copper and 52.8% of chlorine.
Hope this Helps :)
Answer: They are both non polar molecules compounds although water is a polar molecule compound. There are no significant attractions.