Across
- 3. temporary structure formed when reactant molecules meet to undergo a reaction (2 words)
- 5. a chemical property of bases is that they have this (2 words)
- 6. unpaired electrons in a neutral atom that are available for sharing, transferring, or pairing with an electron donated by another atom (2 words)
- 7. fraction for changing units in which the quantity in the numerator is equivalent to the quantity in the denominator
- 9. occurs whenever matter changes from one state to another
- 10. can be measured or observed only when matter undergoes a change to become an entirely different kind of matter
- 12. synthesis, decomposition, single and double replacement, combustion, and neutralization (3 words)Accuracy how close a measurement is to the true value
- 13. used to separate out pure substances in mixtures comprised of particles some of which are large enough in size to be captured with a porous material
- 14. mixture of a metal with ≥ 1 other elements (which could be metals, nonmetals, or both)
- 15. these occur more often in nature than do individual elements; consist of atoms of different elements chemically bonded together in fixed proportions
- 17. [three words] simple diagram that shows only an atom’s valence electrons
- 20. process in which some substances change into different substances (2 words)
- 23. acids and bases do this when dissolved in water (2 words)
- 24. ionic compounds that produce positive hydrogen ions when dissolved in water
- 25. purification process where the components of a liquid mixture are vaporized and then condensed and isolated
- 27. fuel + oxygen → carbon dioxide + water
- 30. measure of how many molecules of that substance are present in a given volume
- 31. Color and indicator type indicating exposure to bases (3 words)
- 33. force of attraction that holds together two nonmetal atoms that share electrons (2 words)
- 35. a substance that increases the rate of a chemical reaction without being altered by the reaction
- 36. ionic compounds that produce negative hydroxide ions when dissolved in water
- 39. alloy of copper and zinc; softer than bronze and easier to shape; very shiny; used for musical instruments, doorknobs, and plumbing fixtures
- 40. mixture in which particles are distributed uniformly throughout and are too light to settle out
- 43. an expression that shows the elements in a compound and the relative proportions of those elements (two words)
- 44. name for N2O3 (2 words)
- 45. the number of these must be equal on each side of a balanced chemical equation
- 49. two ionic compounds exchange ions (3 words)
- 50. reaction type in which the energy released when bonds form exceeds the activation energy
- 53. lowering of the freezing point of a liquid due to presence of a solute (3 words)
- 56. a solid substance in which the particles are arranged in an orderly, repeating, three-dimensional pattern
- 57. number placed in front of a chemical symbol or formula that shows how many atoms or molecules of the substance are involved in the reaction
- 58. conducted experiments showing gases must consist of tiny, individual particles that are in constant, random motion; a given compound is always comprised of the same elements in the same whole-number ratio; different compounds consist of different elements or ratios; and, elements are made of separate, discrete particles that cannot be subdivided.
- 59. concentration of hydrogen ions in a solution
- 60. a certain amount of energy a chemical reaction needs just to get started (2 words)
Down
- 1. a tactile characteristic of bases (2 words)
- 2. state of matter that has neither a fixed volume nor a fixed shape
- 4. intentionally kept constant so it won’t influence the outcome of an experiment
- 8. parts of a measured quantity that are objectively absolutely accurate and independent of who is making the measurement
- 10. representations of chemical reactions that display the reactants and products with chemical formulas (2 words)
- 11. mass number of a nitrogen atom containing 8 neutrons
- 15. metals act well as these because of the constantly moving electrons
- 16. a one-or two-letter designation of an element (two words)
- 18. negatively charged; almost no mass compared to protons; exist outside the nucleus; discovered by J.J. Thomson
- 19. negative ions formed by atoms gaining electrons
- 21. in a chemical reaction, energy is used to ________ bonds in reactants
- 22. vertical column of the periodic table
- 25. concluding specific claim from general observations; both logically and actually true
- 26. factor that researcher predicts will change in response to changes in independent variable
- 27. a force of attraction between atoms or ions formed when atoms share or transfer valence electrons (2 words)
- 28. change from gas to liquid
- 29. positive ions formed by atoms losing electrons
- 32. modern periodic table is organized by arranging elements in order by this (two words)
- 33. many burn easily; many do not dissolve in water; cannot conduct electricity; tend to have low melting and boiling points (2 words)
- 34. reaction type in which the activation energy exceeds the energy released when bonds form
- 37. simplest form of matter that has a unique set of properties
- 38. condition of an atom’s outermost energy level that produces the greatest stability
- 39. raising of the boiling point of a liquid due to presence of a solute (3 words)
- 41. described electrons as orbiting at specific distances from the nucleus
- 42. first proposed atoms, without evidence to support his idea
- 46. state of balance in which the forward and reverse direction rates are equal in each direction, and there is no overall change in the amounts of reactants and products
- 47. “two-atom”
- 48. clues this has occurred include change in color, change in temperature, and production of a gas
- 51. AB → A + B
- 52. a protein that acts as a catalyst for chemical reactions
- 54. = mass divided by volume
- 55. times one billion