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Across
  1. 3. - an equation for a chemical reaction in which mass is conserved and there are equal numbers of atoms of each element on both sides of the equation
  2. 5. - a common sign of a chemical reaction and usually indicates the production of a gas.
  3. 10. - used in a chemical equation to indicate the direction of the reaction
  4. 12. - a substance that is formed as the result of a chemical reaction.
  5. 13. - a key indicator that a chemical reaction has occurred, specifically relating to whether the reaction is endothermic or exothermic.
  6. 17. - When substances react, new substances with different molecular structures and properties are formed, which can cause a change in how light is absorbed or emitted,
  7. 18. - a process in which one or more substances, called reactants, are transformed into different substances, known as products.
  8. 19. - is a type of chemical reaction in which a single, complex compound breaks down into two or more simpler substances
  9. 20. - a small number written slightly below and to the right of an element's symbol in a chemical formula.
Down
  1. 1. - is a type of chemical reaction where one element replaces another element in a compound.
  2. 2. - a numerical value, usually a small whole number, placed in front of a chemical formula in a balanced chemical equation.
  3. 4. - is a chemical reaction in which two compounds, typically ionic compounds in an aqueous solution, exchange their positive ion
  4. 6. - a fundamental scientific principle which states that matter is neither created nor destroyed during a chemical reaction
  5. 7. is a chemical reaction in which a substance reacts rapidly with an oxidant, to produce oxidized products, while releasing significant energy in the form of heat and light.
  6. 8. an indicator of a chemical reaction and is also known by the technical term effervescence.
  7. 9. the starting materials in a chemical reaction that undergo a chemical change to form a product.
  8. 11. - is a chemical reaction that absorbs energy, usually in the form of heat, from its surroundings to proceed.
  9. 14. - is a chemical reaction that releases energy into its surroundings, typically in the form of heat, but sometimes also as light, sound, or electricity
  10. 15. - a symbolic representation of a chemical reaction, showing the reactants and products using chemical symbols and formulas
  11. 16. is a type of chemical reaction where two or more simple substances combine to form a single, more complex product