These would be the elements in row 2 the alkaline metals. Elements in a row usually share many qualities such as electon reactivity as well as similar characteristics like the fact that many alkaline metals are considered Cations, ions with positive charges. Some examples are beryllium and calcium.
You kinda need to put something there? We don’t know what the choices are so there’s really no way we’d know what choice is an example of federalism
Answer:
Xe
Explanation:
Cs and Na are solids in room temperature while F and Xe are gases.
The number of electrons in the outermost shell of an atom will determine its reactivity. Out of the gases given Xe and F, F ( the most electronegative element) posses 5 valence shell electrons which makes it highly reactive while Xe which is a noble gas posses 8 valence shell electrons which makes it less reactive compared to many elements.