If matter is made up of electrically neutral particles such as neutrons

Actually atom is made up of two opposite charged particles the force of attraction between these opposite electric charges is called electromagnetic force is responsible for manifestation of inter atomic and inter molecular forces which take place in the form of tension, friction, normal reaction, contact force etc.

If atoms are made of neutral particles then there will not be any electromagnetic forces. Therefore there will not be tension, friction and normal reaction but gravitational force exists.