How to write reaction equations for the reaction of calcium and dilute nitric acid?

Normally metals react with dilute acid to form a salt and evolve hydrogen gas but I have read that hydrogen gas is not evolved when a metal reacts with nitric acid (because Nitric acid is a strong oxidizing agent). It instead oxidizes the hydrogen evolved to water and itself gets reduced to any of the nitrogen oxides ($\ce{N2O}$ or $\ce{NO}$ or $\ce{NO2}$). Then how to write the equation for the reaction of calcium with dilute nitric acid.

$$\ce{4Ca + 10HNO3→4Ca(NO3)2 + N2O + 5H2O}\tag1$$
$$\ce{4Ca + 10HNO3→4Ca(NO3)2 + NH4NO3 + 3H2O}\tag2$$
• I don't quite believe this. I'd expect a broad range of nitrogen compounds, maybe including $\ce{N2O}$, but most likely not as the main or only product. Moreover, when reacting with diluted nitric acid, calcium will mostly react with water. – Ivan Neretin Jan 11 '17 at 12:09