Explain how to write the chemical formula for sodium (Na +) and the polyatomic ion carbonate (Co2).

Explanation:

sodium (Na +)

Carbonate ion (CO₃²⁻)

Ionic compounds are formed between ions (Anions and Cations).

For a neutral compound to be formed, the charges of the ions must cancel each other out.

Sodium ion has a charge of +1

Carbonate ion has  a charge of -2

The only way to make sure both ions have similar charges is to multiply each ion by the coefficient of the other.

Thus we have;

Sodium ion = +1 * 2 = +2

Carbonate ion = -2 * 1 = -2

From this, the chemical formular of the product formed between both ions must contain 2 sodium ions and one carbonate ion.

This is given by;

Na₂CO3