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
- Elements are organized inthe periodic table.
- Each element has its own symbol.
- 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
- Each molecule of a compound is exactly like every other molecule of that compound.
- Each compound is represented by its own chemical formula.
- 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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