Physical Science 1 st Semester Final Exam Review Chapters 1-7, 8.3-8.4, 10.4 1. What procedures should be followed when working with chemicals in the lab? do not touch, taste, or inhale chemicals; check labels before using; do not remove chemicals from lab area; dispose of waste chemicals properly; wash hands with soap and water after working with chemicals 2. Describe the clothing a student practicing safe lab procedures would be wearing. lab apron; goggles over eyes; long hair tied back; shoes covering the entire foot; no loose sleeves, ties, jewelry etc. 3. What is a scientific theory? A well tested explanation for a set of observations. Theories explain why things happen laws just explain what is happening 4. Give one circumstance under which a scientific theory could be modified. if new observations are made that contradict the theory, it must be modified 5. Research shows that eating large amounts of trans fats can lead to heart disease. Is it ethical for restaurants to serve high trans fat foods? Should consumers be informed about trans fat content in restaurant food? Keep the following in mind ethics is what is considered right or wrong, but the question that always arises is who determines what is right or wrong In order to receive full credit on a question of this nature (one that deals with ethics) 1. Answer the question!! A. In this case, you need to clearly state if you think it is ethical or not B. You also need to state whether consumers should be informed or not That s two points (out of four) right there just for answering the question!!! 2. Give appropriate reasons as to why you answered the question the way that you did A. State WHY you think it is ethical or not ethical B. State WHY you think consumers should or should not be informed of the fat content of their food. Getting full credit for this question is not necessarily WHAT your answer is, but HOW your answer is stated! 6. A student wants to determine the effect of fertilizer on plant growth. The student has 3 plants. Each plant is given a different amount of the same kind of fertilizer and the growth of the plant is recorded (in centimeters). a. What is the dependent variable in this experiment? plant growth b. What is the independent variable in this experiment? amount of fertilizer 7. A graduated cylinder contains 25.0 ml of water. A marble in placed in the graduated cylinder and the water level rises to 26.2 ml. a. Given the mass of the marble is 4.8 g, determine the density of the marble.
d m 4. 8g 4 v 12. ml g ml b. If the marble were placed in a beaker of liquid mercury (density = 13.6 g/ml), would the marble sink or float? Float its density is less than that of mercury. Substances with high densities migrate to the bottom of the container and substances with low densities move to the top 8. Define viscosity. a substance s resistance to flow 9. Use an example to explain what happens to viscosity of a liquid as it is heated. At higher temperatures, viscosity usually decreases and a substance flows more easily hot syrup is easier to pour than syrup that is cold 10. List three physical properties. physical properties are ones that can be measured without changing the substance density, hardness, color, texture, malleability, melting point, boiling point, viscosity 11. What is the difference between a physical and chemical property? a physical property can be measured without changing the substance for a chemical property to be measured, a new substance must be created 12. Give an example of a heterogeneous mixture. mixed nuts, cereal, trail mix, tossed salad 13. Give an example of a homogeneous mixture. salt water, Kool-Aid, air 14. List three ways a mixture can be separated. filtration: separates materials based on the size of the particles distillation: process that separates materials based on boiling point sedimentation: process that separates materials based on differences in density 15. Classify the following as element, compound, or mixture: a. Oxygen Element b. Distilled water Compound c. Air Mixture d. Mg(NO 3) 2 Compound 16. During a phase change, a. what happens to temperature? temperature stays the same during phase changes b. what happens to heat? heat either increases or decreases (depending on whether process is exothermic or endothermic)
17. List three endothermic phase changes. melting, vaporization, sublimation 18. List three exothermic phase changes. freezing, condensation, deposition 19. Draw the particle arrangement for: a. Solid most orderly, particles are tightly packed b. Liquid not as orderly as solids, but more closely packed than gases c. Gas particles are spread very far apart and moving very quickly
20. Identify the phase changes a. Condensation b. Vaporization c. Melting d. Freezing e. Sublimation f. Deposition 21. List the four signs of a chemical change. color change formation of a gas formation of a solid (precipitate) energy given off in the form of heat and/or light 22. Are the following changes chemical or physical? Explain your answer. a. Banana ripening Chemical a new substance is created (rotten banana) and the original banana is no longer present. Also, a color change occurred b. Grinding pepper Physical the pepper is still pepper no new substances were created 23. Explain what happens to the motion of particles as a substance is heated. Particles of a substance will begin to move more quickly and as they move quickly, they usually take up more space 24. The following pressure and volume data was collected. Volume (L) Pressure (kpa) 0.5 200 1.0 100 1.5 70 2 50 a. Graph the data.
Volume vs. Pressure 500 Pressure (KPa) 400 300 200 100 0 0 0.5 1 1.5 2 2.5 3 Volume (L) b. Which gas law is illustrated here? Boyle s law P 1V 1 = P 2V 2 c. Does the graph show a direct or inverse relationship? Explain. Inverse relationship as one the variables increases (volume), the other variable decreases (pressure) d. Use collision theory to explain the difference in pressure in the 1 L container and the 2 L container. (Assume the number of particles remains constant.) The pressure in a container is the result of collisions between the gas particles and the walls of the container. If the volume of the container is increased, the amount of space is increased and the particles do not run into the walls as often (if their speed stays the same, which it will if the temperature does not change). The lower number of collisions results in a lower pressure. 25. Complete the table below: Subatomic Particle Name Charge Location in the Atom Electron -1 outside the nucleus (electron cloud) Proton +1 nucleus Nuetron 0 nucleus 26. Write a detailed explanation of the cathode ray experiment and what was learned about the structure of the atom. J.J. Thomson used the Cathode Ray Tube experiment to discover electrons in the late 1800 s. The Cathode Ray Tube is a glass tube that emits a glowing beam inside the tube when electricity is supplied to either side. This glowing beam was able to be curved using charged plates and magnets, so Thomson knew the beam had to be composed of negative particles (because it curved towards positive charges and away from negative charges). This discovery led Thomson to conclude that the atom was not the smallest particle of matter, but composed of smaller particles one with a negative charge and one with a positive charge to balance the negative. He proposed the Plum Pudding model of the atom where the negative charges were randomly placed in a sea of positive charge)
27. Write a detailed explanation of the gold foil experiment and what was learned about the structure of the atom. Ernest Rutherford performed the Gold Foil experiment in the early 1900 s. The experiment consisted of shooting positively charged particles at a thin foil of gold. Most of the particles passed straight through the foil, but some were deflected and some bounced straight back. From the results of this experiment, Rutherford concluded the following: The atom contains a small, dense, positively charged area which he called the nucleus The atom is made up of mostly empty space The negative electrons surround the small, dense, positive center He called the positively charged particles in the nucleus protons
28. What does Schrodinger s model of the atom say about the location of electrons? The exact location of electrons can never be known. We can only determine the most probable locations for electrons where they will most likely be, but not their exact location. He called these areas of high probability orbitals 29. How did Mendeleev arrange the elements in his periodic table? Increasing atomic mass 30. How are the elements in the modern periodic table arranged? increasing atomic number (or number of protons) 31. Complete the table below: Element Name Name of periodic family Number of valence electrons Draw the Electron Dot Diagram Metal, Nonmetal, or Metalloid? Sodium Alkali Metals 1 * change the Li to Na Metal Neon Noble Gases 8 Non Metal Chlorine Halogens 7 Non Metal Magnesium Alkali Earth Metals 2 metal Silicon Carbon Family 4 metalloid
* change the C to Si 32. Which of the elements listed above is a semi-conductor? How do you know? Silicon metalloids are semi-conductors 33. Use the block to answer the following questions. a. How many protons are in this atom of copper? 29 b. How many electrons are in this atom of copper? 29 c. How many neutrons in a copper-65 isotope? 36 d. Why is there is a.536 written after the 63? 63.546 is the average atomic mass of all copper atoms. Some copper atoms contain different amounts of neutrons (isotopes) and the occur in nature different amounts, so the different masses do not contribute equally to the average 29 Cu Copper 63.546 34. What is an isotope? atoms that contain the same number of protons, but different number of neutrons. They have the same atomic number, but different mass numbers 35. Isotopes have same numbers of protons and electrons. Isotopes have different numbers of neutrons. 36. How does a neutral atom become an anion? gain one or more electrons 37. How does a neutral atom become a cation? lose one or more electrons 38. Complete the following table: Chemically Bonded Elements Types of elements combined (metals or nonmetals) Ionic, covalent, or metallic? Sodium and Chlorine metal & nonmetal ionic Carbon and Oxygen nonmetal & nonmetal covalent Gold and Gold metal & metal metallic 39. Explain what is happening with the electrons in: a. A covalent bond electrons are shared between two nonmetals. This sharing results with each atom achieving a stable electron configuration. The attraction between the positive nucleus on one atom and the negative electrons on the other atom holds the atoms together, which is a covalent bond b. An ionic bond Electrons are transferred between atoms. One atom ends of positive (cation) and one atom ends up negative (anion). These oppositely charged ions will attract one another, which is an ionic bond 40. Give properties of:
a. Covalent Compounds low melting point, low solubility (do not dissolve easily in water), poor conductors of heat and electricity, high volatility (which makes them smelly) b. Ionic Compounds high melting point, good solubility (dissolve easily in water), good conductors of heat and electricity, low volatility, ions arranged in a crystal lattice (very orderly three-dimensional network) 41. Draw the electron dot diagram for oxygen. a. How many electrons does it need to satisfy the octet rule? 2 42. Explain the law of conservation of mass. In normal chemical reactions, mass can never be created or destroyed. The mass of the products must always be equal to the mass of the reactants 43. Balance and classify the following reactions. a. _4_ Fe + _3_ O 2 _2_Fe 2O 3 synthesis b. _2_ KClO 3 _2_ KCl + 3 O 2 decomposition c. Fe + CuCl 2 FeCl 2 + Cu single replacement d. _2_ NaOH + H 2SO 4 Na 2SO 4 + _2_ H 2O double replacement 44. Identify the reactants in 43a. Fe & O 2 45. Identify the products in 43b. KCl & O 2 46. Use the table to write the formula for the following compounds: a. Calcium chloride CaCl 2 b. Magnesium nitride Mg 3N 2 c. Aluminum nitrate Al(NO 3) 3 d. Potassium oxide K 2O Name of Ion Charge of Ion Calcium +2 Chloride -1 Magnesium +2 Nitride -3 Aluminum +3 Nitrate (NO 3) -1 Potassium +1 Oxide -2 47. What is the ph range for a/an: a. Acid
b. Base c. Neutral substance 48. What happens in a neutralization reaction? 49. What is the difference between nuclear fission and nuclear fusion? 50. Today s nuclear power plants use nuclear. Tomorrow s nuclear power plants may use nuclear. 51. Explain what happens in a nuclear chain reaction. 52. In the equation E=mc 2, a. What do each of the letters stand for? b. What does this equation mean?