1. Explain how do determine the number of protons in an atom. Look at the element on the periodic table the atomic number is the number of protons.

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1 Ms. W FINAL EXAM REVIEW KEY: 20F Science CHEMISTRY PROBLEMS 1. Explain how do determine the number of protons in an atom. Look at the element on the periodic table the atomic number is the number of protons. 2. Create an example and explain how to name a covalent compound. 1 (Name of first non-metal + prefix) + 2 (Stem name of second non-metal + ide ending + prefix) NO 2 nitrogen dioxide H 2 O dihydrogen monoxide 3. Explain the difference between covalent and ionic compounds. Give specific examples. Ionic between metal and nonmetal, one gives electron, one takes electron, both to have filled outer shell, transfer of electrons forms ions, stay bonded through attraction. NaCl Na + Cl - Covalent between 2 nonmetals, sharing of electrons so both seem to have full outer shells. No ions formed, bonded together by continued sharing. H 2 O H:O:H 4. Name 5 families on the periodic table and list some of there properties. 1. Alkali metals very reactive, contain 1 valence electron, metals, form ionic bonds with a charge of Alkaline Earth less reactive, contain 2 valence electrons, metals, form ionic bonds with a charge of Chalcogens less reactive, contain 6 valence electrons, non-metals, form ionic bonds with a charge of -2, or covalent bonds, and some diatomic. 4. Halogens very reactive, contain 7 valence electrons, non-metals, form ionic bonds with a charge of -1, covalent bonds and some diatomic. 5. Noble gases not reactive, usually form no bonds, have 8 valence electrons and a full outer shell. 5. Create an example for each of the following reaction types: a. Addition (synthesis) 2 Na (s) + Cl 2 (g) 2 NaCl (s) b. Decomposition 2 H 2 O (l) 2 H 2 (g) + O 2 (g) c. Single replacement CuSO 4 (aq) + Al (aq) Cu (s) + Al 2 (SO 4 ) 3 (aq) d. Double replacement NaNO 3 (aq) + KCl (aq) NaCl (aq) + KNO 3 (aq) e. Combustion CH 4 (g) + 2 O 2 (g) 2 H 2 O (g) + CO 2 (g)

2 6. Explain the term diatomic and name the molecules that show this property. 2 identical atoms combining in a covalent bond to fill their valence shell. Diatomic atoms are highly reactive and bond to each other when nothing else is available. I 2 H 2 N 2 Br 2 O 2 Cl 2 F 2 7. Name 4 characteristics for acids and 4 characteristics for bases Acids sour, contain H +, turn blue litmus red, corrosive, low ph Base bitter, contain OH -, turn red litmus blue, slippery, high ph 8. Describe a neutralization reaction in a chemical formula. Label all compounds. NaOH + HCl H 2 O + NaCl Base Acid Water Salt 9. Draw a Bohr diagram for potassium and fluorine. 10. Draw a Lewis (Electron Dot) diagram for the formation of a covalent bond between carbon and two oxygen. O C O Double bonds are needed each still has 8 electrons around it. 11. Write formulas for the following and label as covalent or ionic: a. Carbon tetrachloride CCl 4 - covalent b. Iron (III) sulfide Fe 2 S 3 - ionic c. Sodium nitride Na 3 N - ionic d. Diphosphorous trioxide P 2 O 3 - covalent e. Berellium Sulfide BeS - ionic

3 12. Name the following and label as covalent or ionic: a. N 2 O 5 dinitrogen pentoxide - covalent b. SiO Silicon monoxide - covalent c. Li 2 O 2 lithium oxide - ionic d. Cr 2 O 3 chromium (III) oxide - ionic e. ZnO zinc oxide - ionic 13. Balance the following reactions and classify the reaction type: a. 2 H 2 + O 2 2 H 2 O - synthesis b. 2 BCl 3 2 B + 3 Cl 2 - decomposition c. CH O 2 CO H 2 O - combustion d. Zn + PbO ZnO + Pb - single displacement e. 2 NaCl + CaBr 2 CaCl NaBr - double displacement f. Fe 2 O H 2 2 Fe + 3 H 2 O - single displacement g. 2 NaCl 2 Na + Cl 2 - decomposition ECOSYSTEMS PROBLEMS 1. Use your dictionary to fill in the blank space of each sentence with the most appropriate word: a. Plants or producers take carbon dioxide from the atmosphere to use in the process called - photosynthesis. b. Carbon dioxide released to the atmosphere through the burning of fossil fuels is called combustion. c. Denitrification is the name for the process in which bacteria convert dead matter back into N 2 in the atmosphere. d. Nitrogen fixation is the process where bacteria convert atmospheric nitrogen into nitrate and ammonia. e. During photosynthesis, glucose are produced and oxygen gas is released into the atmosphere. f. Both natality and immigration occur to increase the population size. g. When members of a population leave to a new area, this is called emmigration. h. The maximum number of a species that can be supported by the ecosystem is referred to as carrying capacity.

4 i. Bacteria in the soil act as the decomposers in the food web. j. An open-population allows for migration of individuals, as well as, natality and mortality. k. Unlike cows or wolf, humans would be described as omnivores, based on their diet. l. The cycling of nitrogen, carbon and oxygen that occurs on earth is collectively known as biogeochemical cycles. m. A species that is close to extinction is endangered. n. A species that is not in immenent danger of extinction, but is at risk because of low or declining numbers is vulnerable. o. Racoons will eat almost anything. They are most accurately called scavengers. p. If you consume only peanuts you would be a primary consumer / herbivore. 2. Construct a food chain. Include one species from 4 different trophic levels: Tertiary consumer, primary consumer, producer and secondary consumer. Label each level with as much detail as you can. 3. Use a diagram and one example to explain the concept of bioaccumulation.

5 4. Explain how the following are density dependent or density independent factors: a. Competition DD increase in population increase competition for resources. b. Disease DD increase in population increases transmission rates of disease. c. forest fire DI destroys land and resources making unsuitable for all regardless of size. d. pollution DI destroys resources, affects food webs, regardless of size. 5. Briefly describe (or draw pictures of and label) the major steps in the: a. carbon cycle b. nitrogen cycle

6 PHYSICS PROBLEMS 1. Describe the word momentum, and give example of objects that have large, small and zero momentum. Mass times velocity, it is a number that represents the inertia of a moving object. Large momentum would be a bullet or a moving bus. Small momentum would be a person walking or the page of a book turning. Zero momentum would be a stationary object like a statue. 2. Briefly describe each of Newton s 3 laws of motion. Give an example for each. 1. Law of Inertia objects tend to resist changes in state of motion directly proportional to size: pushing a car vs. a chair - the larger object takes more force to overcome inertia. 2. F = ma Force is directly proportional to the size of the object. Applied force is directly proportional to the acceleration of the object: pushing chair Lab more force was required to accelerate 2 people on the chair the with the same value. 3. Equal and opposite reactions for each applied force there is an equal and opposite force. Recoil of the gun - trigger explodes bullet forward with force that is equal and opposite to force applied on gun by bullet. 3. Using the following dot pattern, explain the motion of the object at each number: constant velocity, no acceleration 2 increasing positive velocity, positive acceleration 3 decreasing positive velocity, negative acceleration 4 constant velocity (faster than in 1), no acceleration 4. Calculate the average speed for both the cyclist and the roller coaster v ave = Δd / Δt = 70 km - 0 km / 7 h = 10 km/h v ave = Δd / Δt = 120 m - 0 m / 6 s = 20 m/s

7 5. Examine each P-T graph below, and describe the following features: a. Slope of the graph (positive/zero/negative; increasing/constant/decreasing) b. Direction of motion (right/left; away/towards observer) c. Velocity of the object (positive/zero/negative; increasing/constant/decreasing) d. Acceleration of the object (positive/zero/negative) A. B. C. D. d d d d t t t t A. zero, zero (constant), zero, zero B. positive increasing, right away, positive increasing, positive C. positive constant, right away, positive constant, zero (constant) D. negative constant, left towards, negative constant, zero (constant) 6. Fill in the blanks on the following chart: Distance Time Velocity 10.5 m 4.3 s 2.4 m/s 210 m 8.2 s 25 m/s 164 km 1.5 s 110 km/h 7. Calculate the speed of sound (m/s), given that a clap of thunder is heard by an observer 1.5 km away, 4.6 s after the lightning that produced the sound is seen. 1.5 km x 1000 m / 1 km = 1500 m v = Δd/Δt = 1500 / 4.6 s = 326 m/s 8. Calculate the distance in kilometers from Earth to the Moon, given that radio waves traveling at the speed of light (3.0 x 10 5 km/s) take 1.28 s to cover this distance. v = Δd/Δt 3 x 10 5 km/s (1.25 s) = km = km 9. A car is leaving the city and traveling north. As it enters a highway the driver accelerates at m/s 2 for 5 seconds. What is the change in velocity of the car? a = Δv/Δt aδt = Δv Δv = aδt = (4.0 m/s 2 )(5.0 s) = +20 m/s