Answer: A new substance(product) is made from different elements(reactants) joined by chemical bonds
Explanation: To have a chemical reaction the chemical properties must change. Atoms are never created or destroyed during chemical reaction but at least one chemical bond is broken or formed. Evidence of a chemical change include: change of odor, change of color (for example, silver to reddish-brown when iron rusts), and change in temperature or energy, such as the production (exothermic) or loss (endothermic) of heat.