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 exothermic reactions, some of the reactants' potential energy or enthalpy is released into the surroundings, usually in the form of heat. As a result, the enthalpy of the products is less than the enthalpy of the reactants. The enthalpy change for an exothermic reaction is always negative.