Giving Brainliest If you answer this Correct:)

I found this off of google, "These cold packs have a strong outer plastic layer that holds a bag of water and a chemical, or mixture of chemicals, that result in an endothermic reaction when dissolved in water. When the cold pack is squeezed, the inner bag of water breaks and the water mixes with the chemicals. ... As a result, the water cools down."

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The answer should be C forgive me if I'm wrong

materials water oxygen those are the things i can think of in this moment.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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