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
B because once the circuit is burned the lights will all go of
.90 dL is 90 mL because 1 dL is 100 mL
Answer:
invalid
Explanation:
Just imagine doing this experiment MULTIPLE TIMES and one of the trials you get 72 Kcal while in another u get 12kcal. It doesn't make sense. Somewhere in the experiment she went wrong. So its invalid