Br, Rb, Kr, Sr2+ and Se2- are isoelectronic, in terms of electrons and protons, how are
they isoelectronic?

i think slash and

if the temperature drops and becomes cool

then the atmosphere can be freezing as the water vapor in the air is at maximum (100%) and can be severely cold

also can be snowing lightly as the moisture in the air will start to solidify

and btw this is not chemistry but