Enter your Name:   Enter your E-mail Address:  01. If a substance can be decomposed, is it an element or a compound? 02. If a substance can conduct electricity when dissolved in water, what do we classify it as? 03. State the law of definite proportions in your own words. 04. A chemist does two experiments. In one experiment, he finds that 14.0 g of nitrogen combine with 16.0 g of oxygen to make 30.0 g of a compound he calls "compound a." In another experiment, the chemist finds that 48.0 g of oxygen combine with 42.0 g of nitrogen to make 90.0 g of a compound he calls "compound b." The chemist states that the law of definite proportions tells him that "compound a" and "compound b" are two completely different compounds. Why is he wrong? 05. A substance is seen to be brittle and not conduct electricity. Is it most likely a metal or a non-metal? 06. Which theory of matter do scientists believe today: the discontinuous theory of matter or the continuous theory of matter? 07. All scientists today believe that atoms do, in fact, exist. Has their existence been proven? 08. A chemist decomposes 100.1 grams of a substance into 12.1 grams of carbon and 40.0 g of magnesium. The only other product of the decomposition was oxygen, but the gas escaped from the chemist's experimental setup. What was the mass of oxygen gas that escaped? 09. In an experiment to determine how to make sulfur trioxide, a chemist combines 32.0 g of sulfur with 50.0 g of oxygen. She finds that she made 80.0 g of sulfur trioxide and had 2.0 g of left over oxygen. How would the chemist make 100.0 g of sulfur trioxide so that she has no leftovers? 10. To make 44.0 grams of carbon dioxide, you must combine 12.0 g of carbon with 32.0 g of oxygen. If a chemist combines 120.0 g of carbon with 160.0 g of oxygen, how many grams of carbon dioxide will be made? If a substance is left over, indicate whether it is carbon or oxygen, and also determine how many grams are left over. 11. You are told that a molecule contains a total of 17 atoms. If the formula is , what must "x" be? 12. Which of the following atoms would be considered non-metals? W, Ne, Xe, Mn, Fe, S 13. Which of the following compounds would conduct electricity when dissolved in water? 14a. Name the compound 14b. Name the compound 14c. Name the compound 14d. Name the compound 15. What is the chemical formula of sulfur trioxide?