Question

how do metal oxide behave when they react with acids explain by example

Answer 1

When the mettalic oxides are formed they are of basic nature Strong or weak on basis of where they lie in periodic table....And when the base react with acid it give salt and water..
Ex..

Na2o(metallic oxide) +2HCl(acid)---2NaCl(salt) + h2o(water)

Answer 2

Metal oxides are basic in nature. When they react with acid they will make a salt and hydrogen gas will also be evolved. The hydrogen gas evolved will combine with oxygen and will form water.
Iron hydroxide + acid = Iron chloride + water