Answer:
CaCO3 (s)
Step-by-step explanation:
This equation is a double replacement equation, which means that since Na and Cl and paired, Ca and CO3 will be paired.
Then, you look at the charge of each element and balance
Ca has a 2+ charge
CO3 has a 2- charge
The 2+ charge and the 2- charge will cancel so there is no need for a subscript or to balance the equation
The complete equation will be Na2CO3 (aq) + CaCl2(aq) -> NaCl (aq) + CaCO3 (s)
I hope this helps and have a great day!