Give one example in a basic oxide which is insoluble in water.

Hint: In chemistry, periodic tables play a vital role. In the periodic table there are totally \[118\] elements. In the periodic table there are totally \[18\] columns and \[7\] rows. The columns are called groups. Hence, \[18\] groups in the periodic table. The rows are called periods. Hence, totally \[7\] period in the table. Manganese and oxygen are one of the elements in the periodic table. The symbol of Manganese is\[{\text{Mn}}\]. The symbol of oxygen is\[{\text{O}}\]. Manganese is one of the metallic elements in the periodic table. Oxygen is one of the sixteen groups in the periodic table.

Complete answer:
We have to remember that the oxide of sodium, potassium and ammonium are soluble in water and oxides of calcium and barium are partially soluble in water.
Simply said, oxide of alkaline elements are soluble in water. Alkaline elements are first group elements in the periodic table.
Simply said, oxide of alkaline earth elements are soluble in water. Alkaline earth elements are second group elements in the periodic table.
Manganese oxide is a good example in that a basic oxide is insoluble in water.

Note:
We must have to know that the atomic number of the element is nothing but the number of electrons or number of protons. The mass number of the atom is nothing but the sum of the number of protons and the number of neutrons. The atomic number of Manganese is \[25\]. The atomic number of Oxygen is \[8\]. The mass number of Manganese is \[55\]. The mass number of Oxygen is \[16\].Manganese is one of the transition elements in the periodic table.