We can meaningfully talk about concrete dimensions just like before. Atomic radius is mean distance from the nucleus to the boundary of the surrounding shells of electrons.
Because the outer shell of electrons is fuzzy, there are multiple ways to define radius: covalent radius, Van der Waals radius and ionic radius. In molecules atoms overlap in different ways because they share electrons and electrons interact.
There still exists fundamental uncertainty about the location of atoms and molecules. Electrons, atoms and molecules have de Broglie wavelength. For molecules with tens of atoms the wavelength is in the order of picometers.
Because the outer shell of electrons is fuzzy, there are multiple ways to define radius: covalent radius, Van der Waals radius and ionic radius. In molecules atoms overlap in different ways because they share electrons and electrons interact.
There still exists fundamental uncertainty about the location of atoms and molecules. Electrons, atoms and molecules have de Broglie wavelength. For molecules with tens of atoms the wavelength is in the order of picometers.