How are both stability and change seen in properties of elements?

In both natural and built systems, stability and change are an important focus of study for both scientists and engineers. Stability refers to a system that is unchanging. ... A dynamic equilibrium exists when chemical reactions or physical movements occur at rates that balance out, creating no net change in a system.

just did the assignment and the answer was #1 +2 n

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.