More than what fraction of an atom's volume is empty space?

1. Protons and neutrons are packed into a tiny nucleus at the centre. 2. Electrons occupy a vastly larger region around it, but take up almost no volume themselves. 3. Accounting for the sizes of protons, neutrons and electrons, most of the volume of an atom, greater than 99 percent, is in fact empty space. 4. Matter feels solid because of electrical repulsion, not because it is full. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 2 'The Chemical Foundation of Life', sections 2.1-2.3_