Across 5. The energy stored in the chemical bonds of a substance. (2 Words) 8. The substances that undergo change in a chemical reaction. 11. The mass of one mole of a substance. (2 Words) 13. A state in which the forward and reverse paths of a change take place at the same rate. 14. One in which 2 different compounds exchange positive ions and form 2 new compounds. (AB+CD>AD+CB) (3 Words) 15. A reaction in which 2 or more substances react to form a single substance. (A+B>AB) (2 Words) 16. A chemical reaction that releases energy to its surroundings. (2 Words) 17. A chemical reaction that absorbs energy from its surroundings. (2 Words) 18. A reaction in which a compound breaks down into 2 or more simpler substances. (AB>A+B) (2 Words)

Down 1. A substance that affects the reaction rate without being used up in the reaction. 2. A reaction in which electrons are transferred from one reactant to another. (3 Words) 3. A reaction in which one element takes the place of another element in a compound. (A+BC>B+AC) (3 Words) 4. The rate at which reactants change into products over time. (2 Words) 5. The numbers that appear before the formulas. 6. A reaction in which the conversion of reactants into products and the conversion of products into reactants can happen simultaneously. (2 Words) 7. A representation of a chemical reaction in which the reactants and products are expressed as formulas. (2 Words) 9. One in which a substance reacts rapidly with oxygen, often producing heat and light. (2 Words) 10. An amount of a substance that contains approximately 6.02 x 10 to the 23rd power particles of that substance. (Avogadro's Number) 12. The new substances formed as a result of that chemical change.