Answer:
F<S<Mg<Ba
Explanation:
Atomic radius depends of the number of atomic levels filled in the element and of the number of electrons arround it. The more levels filled, and the more electrons arroud, the higher the atomic radius.
Also, the higher the nuclear charge, the lower the radius. The more electrons in the atom, the shielding effect makes the radius bigger.
Combining all this concepts, the order will be:
- Fluorine(F) (50 pm)
- Sulfer(S) (100 pm)
- Magnesium(Mg) (150 pm)
- Baruim(Ba) (215 pm)
Note: the values can vary depending on the method used to measure it.
