1. Is O2 a compound? Explain.
2. Is O2 a molecule? Explain.
3. State the law of conservation of matter, and give an example demonstrating its meaning.
4. Electrolysis is used to break liquid water into hydrogen and oxygen gas. If I begin with 10 grams of liquid water, will the total mass of the two gases be greater than, less than, or equal to 10? Why?
5.What kind of observations can indicate a transfer of energy has taken place in a reaction?