Matter Unit Test Study Guide 1. If you break a pencil (physical change), explain what happens to the atoms in the pencil. Do the atoms in the pencil stay the same, or do the atoms change during a physical change? Explain. 2. If I take 2 atoms of hydrogen and chemically combine them with oxygen, would it create an element or compound? Also, would this be a chemical change or a physical change? Explain. 3. A bowling ball and a soccer ball are the same size. Do they have the same mass, volume or density? Explain. 4. What is the density of a substance that has a mass of 200 g and a volume of 50 cm3? 5. Is dew on the grass in the morning an example of sublimation or condensation? Explain. The atoms in the pencil stay the same. Even in a chemical change, the atoms stay the same, they just chemically combine to form a new substance. It would form a compound (H2O) which is water. You chemically combine those elements so it would be a chemical change. The bowling ball and soccer ball are the same size so they would have the same volume. They do not have the same mass or density. D = M/V D= 200 g/ 50 cm3 D = 4 g/cm3 Condensation because dew forms from moisture (water vapor) in the air that condenses and freezes on the grass.

Matter Unit Test Study Guide 6. Is broccoli and cheddar soup a compound or a mixture? Explain. 7. Give three examples of a compound. 8. What is the universal solvent? 9. If you place an M & M into cold water and then place another M & M into hot water, which M & M would dissolve faster? Explain what happens to a substance’s ability to dissolve (solubility) as you increase the temperature of water when you dissolve something. 10. If you have kool-aid and you mix that with water, what would be the solute, and what would be the solvent? Explain. Broccoli and cheddar soup is a mixture made up of substances broccoli and cheddar. Water (H2O), Salt ( NaCl), Sugar (C6H12O6) Water is the universal solvent because many substances can dissolve in it. The M & M in the hot water would dissolve faster. This is because higher temperatures cause something to dissolve faster. When you heat something it causes the particles in the substance to move faster which helps mix something faster. Kool-aid would be the solute (the substance being dissolved and water would be the solvent (the substance doing the dissolving)

Matter Unit Test Study Guide 11. Put these items in the chart from complex particles to simple particles. Atoms, Protons, Neutrons, Electrons, Molecules.   Molecules Boiling point Atoms Liquid Protons Neutrons Electrons Melting point Gas a. 80*C, 20*C b. Liquid c. It will start to melt to all liquid Solid