Which is of these nonmetals are more reactive— bromine or krypton? explain.

 The  non metal  which  is  more reactive  is bromine

         Explanation

Bromine is in group 17 ( group  of halogens)  which has  one unfilled  spot  in its valence shell.  

Krypton is group 18 ( groups  of noble gases)  which do not  react with  other element  in normal condition due  to  their  filled valence electron.

Therefore since  bromine  has unfilled  valence shell  it is  more reactive  than krypton.

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