Across
- 7. a reaction in which one element is substituted for another element in a compound
- 9. a very important and small unit of measurement that chemists use
- 10. symbolic representations of chemical reactions in which the reactants and the products are expressed in terms of their respective chemical formulae
- 11. a chemical reaction in which less energy is needed to break bonds in the reactants than is released when new bonds form in the products
- 12. anychemical reaction in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron
- 13. the mass in grams of 1 mole of the substance
- 14. a number placed in front of a formula to balance a chemical equation.
- 15. a chemical reaction in which a fuel undergoes oxidation by reacting with an oxidising agent, resulting in the release of energy
Down
- 1. Energy stored in the bonds of chemical compounds.
- 2. reactions that occur when two different atoms or molecules interact to form a different molecule or compound
- 3. reactions in which the reactants absorb heat energy from the surroundings to form products
- 4. a substance that is present at the end of a chemical reaction
- 5. a substance that takes part in and undergoes change during a reaction
- 6. a reaction in which the positive and negative ions of two ionic compounds exchange places to form two new compounds
- 8. a reaction in which a compound breaks down into two or more simpler substances.