Students are challenged to design cold packs for treating injuries. To do this they must find a chemical reaction that absorbs heat energy. The ideal chemical reaction will reach a temperature in the range of 0C to 4C and maintain that temperature for a minimum of 20 minutes.

indium, and thallium have three electrons i think

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

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c. electrical charges of ionic bonds.