Identify the names of the reactants and products in the reaction.
CaCO3 -> CaO + CO2

The names of the reactant and products are:

1. The name of the reactant is calcium trioxocarbonate (iv) (CaCO₃)

2. The names of the products are:

a. Calcium oxide (CaO)

b. Carbon (iv) oxide (CO₂)

In a chemical equation, the reactants are located on the left hand side (LHS) while the products are located on the right hand side (RHS)

With the above information, we can determine which is the reactant and which is the product in the question given above. This can be obtained as follow:

CaCO₃ —> CaO + CO₂

The name of CaCO₃ is calcium trioxocarbonate (iv).

The name of CaO is calcium oxide.

The name of CO₂ is carbon (iv) oxide

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since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.