Enter a net ionic equation for the reaction between nitric acid and calcium hydroxide.

HNO₃ (aq) + Ca (OH) ₂ (aq) - - > H₂O (l) + Ca (NO₃) ₂ (aq)

It is Ca (NO₃) ₂ because NO₃ has a charge of - 1, and Ca has a charge of 2+. And when writing an ionic compound, you take the charge of 1 and write it as the subscript of the other.

Now let's balance the equation and then find the net ionic equation.

2HNO₃ (aq) + Ca (OH) ₂ (aq) - - > 2H₂O (l) + Ca (NO₃) ₂ (aq)

2H⁺ (aq) + 2NO₃⁻ (aq) + Ca²⁺ (aq) + 2OH⁻ (aq) - - > 2H₂O (l) + Ca²⁺ (aq) + 2NO₃⁻ (aq)

We can get rid of the spectator ions. These are the ions that are on both sides.

We are left with

2H⁺ (aq) + 2OH⁻ (aq) - - > 2H₂O (l)

We can simplify the net ionic equation down to

H⁺ (aq) + OH⁻ (aq) - - > H₂O (l)