Based on the models, why do you think helium is number 2( the second element) and beryllium number 4( the fourth element) on the periodic table?

13) a 14) a15) b16) i don't know sorry17) a (maybe)

Ans. : frostbite is when exposure to cold temperatures causes freezing to the skin or other tissues. it most commonly affects the hands, feet, and face. the longer areas are exposed to cold, typically the worse the frostbite. the water temperature used for rewarming a frostbitten part should be : (102 -105) f degrees.

Ithink b not to sure hope that : )