The answer is stress fracture
False Chemical cold packs should be stored in a refrigerator.
A chemical cold pack consists of a bag within a bag. The inner bag contains water. The outer bag typically contains urea or ammonium nitrate. When the inner bag is broken, the water mixes with the chemical in the outer bag, dissolving it. As the chemical dissolves, this is an endothermic reaction. As the reaction absorbs energy, the device cools down.
This cooling will occur independent of whether the cold pack is stored in the refrigerator or not.
<span>The correct answer is D. The US Food and Drug Administration examines many different substances and approves them when their benefits outweigh the risks. To be approved, manufacturers must prove to the FDA that their product is both safe and effective, so if the drug is ineffective, it is unlikely that the FDA will approve it.</span>
