If Earth was the size of an atomic nucleus:

• Taking the Earth as the center, most electrons’ orbitals would be as far as the Sun. The closest one would be as far as the moon. The furthermost one would be about 3 AU, in the middle of the asteroid belt.
• If Mercury had the size of a hydrogen nucleus, Earth would be the size of an oxygen nucleus (2.5x); Neptune & Uranus would be as big as the nucleus of the biggest elements, while Jupiter would be 3x as big as the biggest element and the Sun 30x that.
• If Mercury had the mass of a hydrogen nucleus, Earth would be about a fluorine or neon nucleus by mass. Uranus and Neptune would be in the range of the heaviest known atomic nuclei. Jupiter would be about 20 times heavier than the nucleus of the heaviest element, and the Sun about 20,000 times heavier.