INHERITANCE

Can a usa citizen leave a house to a mexican citizen?... What does the will has to say? and will the mexican citizen get 100% of the property?

A US citizen can leave assets to a foreign national including a Mexican citizen. Typically treaties govern the terms between nations of leaving assets bewteen its citizens. I do not know which treaty covers between US and Mexico, but typically the treaty will say that assets in the US are subject to US estate taxes. So, as long as the US estate taxes are paid it is likely that the Mexican citizen can inherit 100% of the property. All the will has to do is direct that title to the house is to pass to the Mexican Citizen.

Obviously, an attorney retained to draft your will can research this issue in detail. And the estate's attorney will make sure that the will is carried out according to its terms and the law (including the treaty between the US and Mexico).