Elements and Compounds

Next week we are beginning the study of elements and compounds. Students will be able to explain how a small number of naturally occuring elements can result in the variety of substances found in the world. Studentst will also be able to classify substances as elements or compounds.
  • There are between 88-92 naturally occuring elements on Earth
  • These elements form many different molecules and compounds, like H20 and CO2
  • 2 or more elements combine chemically to form compounds
    • C + O + O = CO2 (carbon dioxide)
    • H + H + O = H20 (water)
    • Na + Cl = NaCl (sodium chloride-table salt)
  • There are a huge number of possible combinations of elements to form compunds and mixtures

ELEMENTS-pure substances that make up all matter, cannot be separated 

  1. Elements are organized inthe periodic table.
  2. Each element has its own symbol.
  3. Some elements and symbols students should know and be familiar with: Carbon (C), Hydrogen (H), Oxygen (O), Iron (Fe), Nitrogen (N), Sodium (Na), Argon (Ar), Helium (He), Copper (Cu)

COMPOUNDS-2 or more different elements chemically combined

  1. Each molecule of a compound is exactly like every other molecule of that compound.
  2. Each compound is represented by its own chemical formula.
  3. Some compounds and formulas students should know: Carbon Dioxide (CO2), Water (H2O), ammonia (NH3), table salt (NaCl). Students have been given a list and have been asked to commit 5 to memory. 

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