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 all exothermic reactions the reactants will have higher energy than the products. the answer is pretty much the same as why freezing is an exothermic reaction-- because the release of energy is occurring as bonds are forming. to form bonds, energy must be inputted or it won't happen naturally.