1)can we talk about covalent ,crystalline and van der waals radius in case of a single element? in one book i saw covalent and crystal radii values in case of Sodium .
2)is there any restriction over using crystalline radius in case of only metals ?in the same way covalent radius in case of non_metals ?
3) if comparison of covalent and crystalline radius not possible in case of one element ,how can we say that crystalline radius greater than covalent radius ?
how do we get this order: vander waal radius >crystalline>covalent?
4)in metallic bond theory i read over lapping outer most shell among neighbour metal atoms . how the crystal radius is larger than covalent radius?