If neutrons exert only attractive force, why don't we have a nucleus containing neutrons alone?

A neutron exerts a force on a proton which

Why don't we hear sounds when our ears are closed?

If there is an attractive force between all objects, why do we not feel ourselves gravitating toward massive buildings in our vicinity ?

Which is the only isotope that does not contain a neutron?

Why neutrons in the nucleus are stable?

If heavier bodies are attracted more strongly by the earth why don't they fal faster than the lighter bodies?

Consider two pairs of neutrons. In each pair, the separation between the neutrons is the same. Can the force between the neutron have different magnitudes for the two pairs?

An atom of an element has 13 electrons and mass number 27. the nucleus of this atom contains ________ neutrons.