Atomic radius of the alcaline metals

A simple model created in Tinkercad to show students how the atomic radius change in the alcaline metals. The spheres represent the atoms of the alcaline metals, in scale.
Lithium has an atomic radius of 152 pm (picometers) and was printed with 15,2 mm in diameter. The other numbers are in the table in the images. I found it easier to scale the spheres in this way, so the atoms would not be too big, but it would be easy to make the model in any size.
The spheres were glued to the base to make it easier to pass around the students.