CHEM Lessons 1 & 2

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Across
  1. 1. An organized chart of elements arranged by atomic number.
  2. 6. Digits in a measurement that include all certain digits and one estimated digit.
  3. 8. The reactant that is used up first and determines the amount of product formed.
  4. 10. A compound formed when nonmetals bond together.
  5. 12. An atom has 17 protons and 18 electrons. What is its charge?
Down
  1. 2. Write the name of the molecular compound N₂O₄.
  2. 3. A problem-solving method that uses conversion factors to cancel units.
  3. 4. Nitrogen and hydrogen react according to the equation N₂ + 3H₂ → 2NH₃. If 5.0 moles of N₂ react completely, how many grams of NH₃ are produced? (Round to the nearest whole gram.)
  4. 5. A method of expressing very large or very small numbers using powers of ten.
  5. 7. The ratio of mass to volume of a substance.
  6. 9. The calculation of quantities in chemical reactions using balanced equations.
  7. 11. An atom has 11 protons and 10 electrons. What is its charge?