1. Matter Review
Physical Science

2. 1. Define each of the following:
Atom- The smallest unit of an element that keeps the properties of that element
Element- a substance that cannot be broken down into simpler substances by chemical means
Compound- a substance that is made up of atoms of different elements. When elements combine to form a compound, they always combine in the same proportion. Compounds are represented by chemical formulas.
Mixture- made up of more than one type of substances.
Chemical change- occurs when a new substance is formed
Matter- anything that has mass and takes up space
Pure substance- has a fixed composition
2. Because the substances found in a mixture are not chemically combined (bonded), they are easier to separate. Tell how each of the following methods could be used:
Filtering – to separate a solid from a liquid (ex: sand and water)
Magnetism – to separate magnetic substances from a mixture (ex: iron filings)

3. 3. Many physical properties are useful because they can help to identify an unknown substance. Name 3 physical properties that can be used in this way. Color, shape, size, temperature, mass, boiling point 4. Identify each of the following as an element or a compound: Water- C gold- E oxygen- E Carbon- E sugar- C carbon dioxide- C Hydrogen- E salt- C iron-E

4. 5. Tell whether each statement is describing a mixture or a compound: -forms a new substance- compound -alloy of steel- mixture -each part retains its own properties- mixture -can see different parts- mixture -composed of atoms from different elements that have chemically combined- compound -must be chemically separated- compound -could be separated by filtering- mixture -can be separated by physical means- mixture

5. 6. Tell whether each statement is describing a homogeneous (solution) or a heterogeneous mixture: -could be separated by filtering- Heterogeneous -looks the same throughout- Homogeneous -formed by dissolving something- Homogeneous -can see the various components- Heterogeneous 7. Which of these is a chemical property? flammability, able to oxidize, color, melting point of 50 ̊ C, reacts with acid, mass, fading of paint, good heat conductor, dissolves in water, combustible, high viscosity Flammability, Oxidize, Reacts with Acid, Fading of Paint, Combustible

6. 8. What is viscosity. A measure of the resistance to flow of a fluid
8. What is viscosity? A measure of the resistance to flow of a fluid. Which has the higher viscosity…syrup or water? Syrup because it has a greater resistance to flow than water. 9. Calculate the density of a gas that has a mass of g and a volume of 6.4 mL. Use the formula D=m/v g/mL 10. A substance has a mass of 500 g and a volume of 252 mL. What is the density? 1.98 g/mL

7. 11. In order to float in water, a substance must have a density that is LESS than the density of water (which is 1.0 g/mL). Which of the following substances will float in water? Air = .001 g/cm3 Yes Corn oil = .93 g/cm3 Yes Glycerin = 1.26 g/cm3 No Corn syrup = 1.38 g/cm3 No Wood = .85 g/cm3 Yes Steel = 7.81 g/cm3 Definitely Not Rubber = 1.34 g/cm3 No Ice = .92 g/cm3 Yes

8. 11. In order to float in water, a substance must have a density that is LESS than the density of water (which is 1.0 g/mL). Which of the following substances will float in water? -Air, Corn oil, Wood, Ice 12. Does each statement describe a solid, a liquid, or a gas? -has the most kinetic energy—gas -definite shate, definite volume—solid -has a definite volume, but no definite shape—liquid -move very little—solid -particles closest together—solid -will take shape of container, but has a stronger attractive force than gases—liquid -will hold its shape without a container—solid -made up of particles in motion—gas

9. 13. What happens to the motion of the particles of a substance when the temperature increases? -motion increases 14. A substance melts from a solid to a liquid. Is this a physical or chemical process? Explain why. -physical because it is making a phase change 15. While a substance is changing phase, what happens to the temperature? -temperature doesn’t change (boiling point is always 100 degrees C or melting point is always 0 degrees C) 16. While a substance is changing phase, what happens to the amount of energy? -Energy is added as a phase change occurs

10. 17. What is the name of each of the following phase changes?
-solid to liquid—melting
-liquid to gas—boiling
-gas to liquid—condensation
-liquid to solid—freezing
-solid directly to gas—sublimation
-liquid to gas (not at the boiling point)—evaporation
18. Use the graph to answer the following questions:
What is the melting point of the substance?
20°C
b. What is the boiling point of the substance?
50°C

11. c. How do you know if the temperature is increasing
c. How do you know if the temperature is increasing? -the diagonal on the graph is increasing upward d. How do you know if the substance is changing phase? -a horizontal line, or slope of zero, indicates a phase change 19. A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 g. What is the density of the wood? Would the piece of wood float in water? D=m/v D=80.0g/(3.0cm x 6.0cm x 4.0cm) D=80.0g/72cm^3 D=1.11 g/cm^3 It would NOT float in water because it is more dense than water.

12. 20. OMIT 21. What is the volume of a tank that can hold kg of methanol whose density is g/mL? D=m/v V=m/D V= g/ g/mL V= mL 22. What is the density of a board whose dimensions are 5.54 cm x 10.6 cm x 199 cm and whose mass is 28.6 kg? D=28600 g/ cm^3 D=2.45 g/cm^3