1. Solid copper reacts with solid sulfur to form solid copper(I) sulfide.2. Nitrogen monoxide gas reacts with hydrogen gas to form ammonia gas and water vapor.3. Solid iron(III) oxide reacts with carbon monoxide gas to form solid iron and carbon dioxide gas.

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.