Imagine that you have isolated a mysterious liquid from a sample of food. you add the liquid to a beaker of water and shake vigorously. after a few minutes, the water and the other liquid separate into two layers. to which class of biological molecules does the unknown liquid most likely belong

I believe the liquid is in a class of biological molecules called  lipids. One property of lipid is that they are water soluble (hydrophobic), a property that is put to use in the organisation of cells and tissues. Therefore, lipids can not form bonds with water because they are non-polar and therefore a mixture of lipids and water is immiscible, like the case of the liquid of concern.

Anions are negative charged ions

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.