FINAL EXAM REVIEW – ANSWER KEY

1. A student designed an experiment to study how temperature affects the rate at which enzymes digest protein. She put equal masses of liver into four equal-sized test tubes, brought the test tubes to different temperatures, introduced equal amounts of enzyme into each tube and measured the duration of the chemical reaction. What factors were held constant in the experiment?

Constants are things that stay constant or the same through every trial of an experiment. For this experiment they are: Mass of liver, test tube size, & amounts of enzyme.

2. A student hypothesized that robins prefer large bird houses to small ones. He built four bird houses of different sizes to test his hypothesis. What was the independent variable in the student’s study?

The independent variable is the cause in an experiment, the dependent variable is the effect of the experiment. The cause or the factor that is intentionally changed is the size of the bird house. The effect or what changed in the experiment is the number of birds at each house.

Base your answers to the following questions on the information and diagrams below.

Saltwater plants of the same species were grown in soil in separate containers with 1 liter of water. All of the plants were the same height at the beginning of the experiment. Different amounts of salt were dissolved in each container as shown in the diagrams. All other conditions were held constant. Measurements for the final height of each plant are provided.

3. What is the problem or testable statement for this experiment?

The problem is the question the experiment tries to answer. In this experiment different amounts of salt were dissolved in water, and the plant growth was measured. The question would have to be something like: Does the amount of salt dissolved in water affect the growth of a saltwater plant.

4. Write a possible hypothesis for this experiment.

The hypothesis is a testable statement, NOT A QUESTION! It is a prediction as to what will happen, NOT A QUESTION AS TO WHAT WILL HAPPEN! The hypothesis should be something like this: As more salt is dissolved in water, it will make the plants grow faster. The independent and dependent variables are always contained within the hypothesis.

5. What is the dependent variable for this experiment?

The independent variable is the cause in an experiment, and the dependent variable is the effect. The independent (cause) is the amount of salt, and the dependent (effect) is the growth of the plant.

6. What is the control for this experiment? A control is the trial or group in the experiment that gets the least or no treatment from the independent variable. It is the one that doesn’t get any special treatment. In this experiment the amount of salt dissolved in water is the independent variable. The group that gets the least salt is the control and that is the container with no salt.

7. Define atom.

The smallest unit of an element consisting of a nucleus made of protons and neutrons and an electron cloud that surrounds the nucleus.

8. What is the difference between an element, a compound and a mixture? Give an example of each.

An element is a substance that consists of only one type of atom. (iron (Fe), hydrogen(H), calcium(Ca), cobalt(Co), etc.) A compound is when two or more elements are chemically combined. This means they cannot be separated by anything other than a chemical reaction. A chemical reaction means that the substances you have at the end of the reaction are different from the substances you started with. (carbon dioxide(CO2, water(H2O), salt(NaCl), etc.) A mixture is when 2 or more substances are combined, but they do not change the original substances. They can be sorted, filtered, or otherwise be separated by physical means. (Raisin bran, rocky road ice cream, salt water, cool aide, trail mix, etc.)

USE THE PERIODIC TABLE TO ANSWER QUESTION #9

9. Which element has 13 protons, 14 neutrons and 13 electrons?

When identifying an element the only number that matters is the atomic number. The element with 13 protons, or the atomic number 13, is Aluminum.

10. Given a periodic table:

How do you find the number of protons in an element? Equals the atomic #

How do you find the number of neutrons? The number of neutrons equals the atomic mass minus the atomic number. The atomic mass is the average number of the total number of protons and neutrons in the nucleus. The atomic number is the number of protons, so by subtracting them from the total will leave you with the number of neutrons.

How do you find the number of electrons? The number of electrons is equal to the atomic number. When the number of electrons is different than the atomic number it is called an ion. Ions can be positive or negative depending if the atom gains or loses an electron. On this exam the questions do not involve ions, so the number of electrons will equal the atomic number.

(ml) milliliter 11. The unit used to express liquid volume.

(m) meter 12. The unit used to express length.

(g/mL) grams per milliliter 13. The unit used to express density.

(g) grams 14. The unit used to express mass.

15. Liquid displacement (water displacement) is how to find the volume of an irregularly- shaped object. (Hint: putting it in a graduated cylinder and measuring the difference.)

16. Find the volume of the object using the graduated cylinders below.

Final Volume = 49mL

Initial volume = 33mL

Volume of object = 16m

17. Using the picture, the mass of the object is 30 g

18. Given the mass from Q. #17 and the volume of the object from Q. #16, what is the density of the object? (D = M/V)

30g/16mL = 1.875 g/mL

1.875 g/mL

19. Convert 2.37 grams to:

Kilograms = 0 .00237 kg centigrams = 237 cg milligrams = 2370 mg

20. Compare and contrast the 3 states of matter. Include information about each one’s shape, volume, the arrangement and motion of particles.

Solid: have definite shape, particles have the least amount of energy (heat), vibrating the slowest, particles are closer together, volume is typically the smallest.Liquid: no definite shape, will take the shape of the container, particles have more energy (heat)than in the solid state at the same pressure, particles move more freely and there is more space between them, volume is usually between solid & gas.Gas: no definite shape, will fill entire volume of container, particles have the most energy (heat), particles are very far apart are able to move freely and very quickly.

21. Below are examples of physical and chemical changes. Place a Letter P next to the physical changes, and a Letter C next to the chemical changes.

A physical change is a change in size, shape, or state. It is still the same substance. If you carve a sculpture out of wood, it is still wood. A melted ice cube is still water. A chemical change leaves you with a different substance than you started with. Sodium(Na) + Chlorine(Cl)= salt- sodium chloride(NaCl) Burnt wood is no longer wood, it is ash.

C rusting metal P ripping paper C burning wood P water freezing

P salt dissolving in water C mixing 2 liquids and a gas evolves.

22. Define conduction, convection, radiation and give an example of each.

Conduction: heat transfer through direct contact- objects must be touching each other. Vibrating molecules bump into each other transferring energy. Ex: When an ice cube melts in your hand.

Radiation: heat transfer through empty space by electromagnetic waves. Molecules absorb the electromagnetic waves, gain energy, vibrate faster. Ex: The ground warmed by the Sun.

Convection: heat transfer in a fluid. (liquid or gas) As a fluid is heated, it becomes less dense as the particles spread out. As they spread out they become less dense and rise. Cooler material is more dense and falls. The fallen material is then heated and rises. As it rises it cools. The process keeps repeating and convection currents are the result. Ex: Air warmed at the Earth’s surface, rises, cools, and falls causing areas of high and low pressure. Movement of the asthenosphere in the mantle, heated material rises then cools and sinks, pushing on the crust causing the Earth’s plates to move.

23. Using a colored pen/pencil, draw arrows to show how smoke would move if a lit punk was placed in tube A. Travel down A, and up B.

24. Why does the air flow in this direction? Heated less dense air over the candle causes low pressure, cooler more dense air over the ice creates high pressure. Air moves from high pressure to low pressure.

A B

25. Define: renewable resource – A resource that is constantly being replenished, or has an unlimited

supply. Ex: Solar, wind, geothermal, etc.

non-renewable resource – A resource that cannot be replaced with in a lifetime. Ex: fossil fuels,

coal, oil, etc.

26. How are rocks and minerals similar? How are they different? Minerals are a naturally occurring inorganic solid with crystal structure and definite chemical composition. Most rocks are made from minerals, but can include other things as well, such as organic material from living things. All minerals samples can be classified as rocks, but not all rocks are minerals.

27. Define:

Igneous rock: rocks made from cooling melted or molten material.

Sedimentary rock: Rocks made from fragments of other rocks. The fragments can be broken of pieces or they can be dissolved in water.

Metamorphic rock: An existing rock that is changed through heat, pressure, and chemicals.

28. What is the relationship between cooling rate and crystal size in an igneous rock?

When an igneous rock cools slowly it has time to grow large crystals. As it slowly cools some minerals will turn solid before others. They will float around the rest of the melt accumulating together with other similar solid crystals growing larger and exhibiting a definite crystal shape. (ex: granite) When an igneous rock cools quickly its crystal grains are very small. They don’t have the time to grow large and are just locked into solid form with other random minerals that will not have a defined crystal shape.

29. Name and describe the 5 agents of physical weathering.

1) Temperature change- thermal expansion and compression crack rock2) Pressure change- release of pressure causes rock to crack.3) Animal action- the activity of animals wear rock down.4) Abrasion- wind, water, & gravity acts on rocks as particles scrape against them in the wind, water or

fall.5) Plant growth- plant roots help crush and break up rock.

30. Number the following in order from the most permeable (#1) to the least permeable (#4). Permeability is how easy water can flow through the soil.

silt/mud 4 coarse sand 2 gravel 1 fine sand 3

31. How are continental crust and oceanic crust different? How does this affect the outcome (features formed) when they collide?

Continental crust is made of the less dense rock granite, and oceanic crust is made of the more dense rock basalt. The more dense rock will sink, or be subducted, under the continental crust. As that crust sinks it crumples the continental crust, and the oceanic crust starts to melt while bringing water in with it. This creates pockets of thick sticky magma with a lot of gases, which in turn creates a chain of volcanoes on the continent along that plate boundary.

32. How did scientists get information about the interior of the Earth?

By studying seismic waves. By seeing how the seismic waves change, scientists can infer what the material it

is traveling through is or what its properties are. Ex: P waves travel through all substances, S waves cannot

travel through liquids or gases. The places on the Earth where S waves do not reach tells scientists that the

outer core is liquid.

33. Describe the evidence Wegener used to support the Theory of Continental Drift. What evidence was he lacking to help prove his theory?

Wegener collected evidence from:1) Fossils- fossils of the same species were found oceans apart with no way of traveling there.2) Landforms- the continents seemed to fit together like a puzzle, mountains, plains, and coalfields on

adjoining pieces matched when the puzzle was assembled.3) Climate- glaciers in Africa and tropical fossils of plants on islands in the arctic circle indicate that their

positions had changed.

34. Define the three types of stress and identify the type of fault they create and which boundary they are associated with. Also list the features formed at each type of boundary.

1. Tension: pulling apart, divergent boundary, normal fault- head wall moves down in relationship to the foot wall. Mid-ocean ridges; rift valleys; new ocean floor

2. Compression: pushing together, convergent boundary, reverse fault- head wall moves up in relation to

the footwall. Trenches, volcanic mountains, island arcs, folded mountains

3. Shearing: sliding past each other in opposite directions, transform boundary, strike slip fault- slipping past each other side by side

35. According to the theory of sea-floor spreading, where on the ocean floor are the youngest and oldest rocks found?

New crust is created at the mid ocean ridge when molten material cools, as more crust is made the older crust is pushed aside. Therefore, young crust is found close to the ridge and old crust is further away.

36. If the difference in arrival times of the P and S waves is far apart, what is true about the distance to the epicenter? * Know how to read the graph from the epicenter lab.

P waves travel faster than s waves. Therefore the further the waves travel, the p wave will increase the distance between them. This causes the time elapsed between their arrivals to increase with distance.

37. Where are most earthquakes and volcanoes found? Why?

They are found at plate boundaries. That is where subduction, compression of plates, plates grinding and slipping past each other occur. That is where most of the processes that cause earthquakes and volcanoes happen.

38. Define a hot spot volcano.

When there is a particularly hot spot in the mantle, the magma will melt through the crust and make a chain of volcanoes that follow the plate movement. Ex: the Hawaiian islands.

39. How do temperature, gases and silica affect the viscosity of lava and how a volcano will erupt?

The more viscous (sticky or resistive to flow) a magma is the more explosive the volcano is. The more silica the more viscous magma is. The cooler the magma the more viscous it is. The more trapped gases the more explosive the magma will be. It will act like a soda bottle that was shaken up.

40. Describe the difference between a shield, cinder cone and composite volcano.

Shield volcano is made from low viscosity/low gas magma resulting in a relatively flat gentle sloping mountain with quiet eruptions. Ex: Hawaii

Cinder cone is made from cinders and ash piling up, can be violent, usually has steep sides.

Composite is made from alternating layers of cinders/ash and lava flows. Make up some of the most violent volcanoes.

41. What are the four main layers of the atmosphere and what determines where one layer ends and another begins?

From lowest to highest: Troposphere, stratosphere, mesosphere, thermosphere. Changing temperature determines the layers. As you rise in altitude temperature decreases in the troposphere & mesosphere, and rises in the stratosphere & thermosphere.

42. What happens to air pressure as you go from the surface of the Earth upward through the atmosphere?

The pressure and density decreases.

43. What is air pressure and how do you measure it?

Air pressure is the weight of the air pressing against something. Air pressure is measured with a barometer.

44. In what ways does burning fossil fuels negatively affect the Earth’s energy budget?

The Earth’s energy budget is balanced by the heat the Earth receives from the Sun compared to how much heat escapes back to space. The burning of fossil fuels adds greenhouse gases to the atmosphere which traps more heat on the Earth, throwing the energy budget off from the levels we are used to.

45. List and describe the four air masses that affect the United States in terms of temperature and humidity. Tropical- warm, Polar- cold, Continental- dry, Maritime- humid

1. Continental polar- cold, dry

2. Continental tropical- warm, dry

3. Maritime polar- cold, wet

4. Maritime tropical- warm, wet

46. Which wind belt moves weather across the United States?

Westerlies- winds move away from the horse latitudes and are bent from the west to the east as a result of the coriolis effect.

47. The deflection of the winds due to the Earth’s rotation is called : Coriolis effect

48. As the wet and dry bulb temperatures get closer together, what happens to relative humidity?

Evaporation is a cooling process. When water evaporates it cools the substance it evaporates from. When humidity is high, not much evaporation takes place- meaning the wet bulb is not cooled much and the temperatures are close. When humidity is low, a lot of evaporation takes place cooling the wet bulb- meaning the wet bulb will be at a much cooler temperature.

49. How do clouds form?

As air rises it cools. If the air is humid and cools to the dew point, then condensation starts to occur. The condensation forms a cloud.

50. Name the cloud that is:

high in altitude and made of ice crystals Cirrus

puffy Cumulus

layered and produces drizzle Stratus

a storm cloud Cumulonimbus

51. How do greenhouse gases affect the Earth’s temperature?

They help trap heat on the Earth. Refer to question 44

52. Describe the difference in heating and cooling rates of soil and water.

Soil has a lower specific heat than water, so it heats and cools faster. Water having a higher specific heat, takes longer to heat up but retains the heat longer.

53. What kind of weather is associated with a low pressure system?

Low pressure air is warmer, less dense, rising air, as air rises it cools, creating clouds and often some form of precipitation.

54. What kind of weather is associated with a high pressure system?

High pressure is cooler air that is denser and sinking, clouds dissipate, making clear skies.

55. What kind of weather follows a cold front?

During the cold front, clouds and a storm may occur; will most often be followed by cooler, dry, clearer

weather.

56. What kind of weather follows a warm front?

During the warm front, clouds and a rain or snow shower may occur; will be followed by clearer, warm,

possibly humid weather.

57. Draw a station model: *refer to key on page 214 in Module F Earth’s Weather & Atmosphere book.

Air pressure 29.2 inches Overcast/cloudy skies65 29.2 Air temperature 65° F .3 inches of precipitation

56 .3 Dew point temperature 56° F Wind speed: 14 mph Wind direction: southwest

58. How does the tilt of the Earth’s axis and revolution affect seasons?

The Earth’s tilted axis causes the angle of the Sunlight hitting different parts of the Earth to change as well the amount of time different areas have daylight as it revolves around the Sun. The more direct the Sun’s rays and the longer you are exposed to them, the warmer the season will be.

59. During a lunar eclipse, the moon is in the ___________Full___________ phase.

In order for the Earth’s shadow to fall on the Moon, the Moon must be opposite from the Sun.

During a solar eclipse, the moon is in the ___________New_______________ phase.

In order for the Moon’s shadow to fall on the Earth, the Moon must be between the Earth & Sun.

60. Which 2 positions would the moon be in during a Spring tide? _A__ & _C__

The Sun, Earth, and Moon must be in a straight line for the gravitational pull to combine.

Neap tide? B & D

When the Moon, Earth, & Sun are at right angles the Sun & Moon’s effects on the tide partially cancel, result in little difference between high and low tide.

61. As the moon moves from position C to position A, the amount of light on the moon’s surface

Decreases: Position “C” is the full moon, where the entire lighted side of the Moon is seen- position A is the New Moon where none of the lighted side can be seen

62. As the moon moves from position A back to position C, the amount of light on the moon’s surface

Increases: New Moon none of the lighted side is seen to full Moon when the entire lighted side is seen.

C

D

B

A

63. What two factors keep the planets in orbit around the sun?

Gravity & Inertia: Gravity pulls the planets towards the Sun, inertia is the planets motion trying to move in a straight line away from the Sun. The 2 forces are balanced causing a stable orbital path around the Sun.

64. The spinning of the Earth on its axis is called Rotation. 65. The Earth travelling once around the Sun is called Revolution.

66. The moon goes through phases because of its orbit or revolution around the Earth.

67. Using the H-R Diagram:

Where are the brightest, hottest stars? Upper left

Where are the coolest, dimmest stars?Lower right

Compare Rigel to Sirius B.

Rigel and Sirius B are both similar in surface temperature, but rigel is much brighter and larger than Sirius B. 68. A star the size of the sun will become a white dwarf when it dies.

A star the size of our Sun does not have enough mass to fuse elements heavier than carbon. When all of its fuel is exhausted it will blow off its outer layers and leave behind a small dense hot core that will glow for a very long time as it cools.

69. A massive star will become either a _Neutron star__ or Black hole at the end of its life cycle.

A massive star will fuse heavier and heavier elements until it reaches iron, which is the point when nuclear fusion is no longer sustainable. The star contracts violently under gravity with no outward nuclear force to stop it resulting in a supernova. Depending on the mass remaining determines if it will become a black hole or a neutron star.

Type X Type Y Type Z

70. Which galaxy is: _Z_ irregular __X__ spiral ___Y__ elliptical

Spiral is pinwheel shaped, lots of gas and new star formation. Elliptical is oval shaped, older, not much gas, almost no new star formation. Irregular is the result of the collision between galaxies.

71 Compare the inner planets with the outer planets.

The inner planets are solid, rocky, have shorter orbital periods, few if any moons, no ring systems, and are much warmer.The outer planets have no solid surface, are made of gas, long orbital periods, many moons, have ring systems, and are much colder.

72. How does distance from the sun affect a planet’s orbital period?

The closer a planet is to the Sun, the faster it needs to move to keep in orbit. The closer a planet is to the Sun, the shorter its orbital period.

73. What is red shift and how does it support the Big Bang Theory?

When light emitted from an object and it is moving toward you, the waves will start to bunch up causing the light to have a higher frequency, and shifting the light toward the blue end of the spectrum. When light emitted from an object is moving away, the waves get stretched out causing the light to have a lower frequency, and shifting the light to the red end of the spectrum. If all of the observed galaxies’ light is shifted to the red that means they are all moving away from each other. If we reverse that motion, it is like watching a movie in reverse. All of the galaxies will combine into a single point. A massive explosion, “The Big Bang”, explains the red shift.

74. What is the difference between a meteoroid, meteor and meteorite?

A meteoroid is a rock in outer space.

A meteor is when a meteoroid enters the Earth’s atmosphere and starts to burn up.

A meteorite is when a meteor reaches the Earth’s surface.