If you are a meat eater, you are less likely to suffer from zinc deficiency as meats are one of the best foods rich in zinc. The meats that have the highest concentration of zinc include beef, lamb, pork, chicken and turkey. A 100 gram serving of cooked lean beef contains 12.3 mg or 82% DV of zinc.
Endothermic reactions absorb energy from the surroundings, while exothermic reactions release energy to the surroundings. Fuels release energy when they burn. The energy output of a fuel can be measured by calorimetry using a known mass of water.
In order to condense water vapor to water, the molecules must lose energy. Chemistry at About.com states that most exothermic reactions, unlike phase changes, result in higher entropy in the products. An example of an exothermic reaction that is not a phase change is combustion. After wood burns, the result is much less ordered than the reactants that went into the reaction, according to Scientific American.