Which element does not contain any neutrons

There is only one stable atom that does not have neutrons. It is an isotope of the element hydrogen called protium. Protium, which contains a single proton and a single electron, is the simplest atom. All other stable atoms contain some number of neutrons.

16- counting by fours

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.