B. Engineers perform lots of trials.
<span>The rate of conductivity is different among different substances, like aluminum, steel, and copper. Aluminum conducts heat the fastest at 910 j/kgaac. Steel is next and conducts heat at 450 j/kgaac. Copper conducts heat the slowest at 390 j/kgaac.</span>
<span>Negatively charged particles will go toward the positive end of the magnetic field and positively charged particles will go toward the negative end.</span>