Eleventh Grade Science FCAT Review Session

1. Eleventh Grade Science FCAT Review Session February 22, 2007

2. Process of Elimination • For multiple choice questions use the process of elimination. • Look for two similarly worded answers. Often, one of these two is the answer. • Cross out any answers you KNOW are wrong. • Eliminate answers that are too extreme, negative, or absolute (NEVER or ALWAYS). • Verify your answer by checking your calculation or double checking the information provided whether in text or chart. • If an answer seems too easy, it usually is.

3. Strand A – The Nature of Matter • Physical Change – occurs when a physical property (size/shape) of a substance is changed; many physical changes can be undone. Ie, folding paper • Chemical Change – occurs when a one or more substances are changed into new substances with different properties; cannot be undone by physical means

4. Strand A – The Nature of Matter • Defining Features • Solid • Keeps it shape and volume • Liquid • Takes the shape of its container • Keeps the same volume, in a container or not • Can flow • Gas • Takes the shape of its? • Takes the volume of ? • Can ?

5. Strand A – The Nature of Matter • Boiling Point – temperature at which a substance changes from a liquid state to a gaseous state • Freezing Point – temperature at which a substance changes from a liquid state to a solid state • Melting Point – temperature at which a substance changes from a solid state to a liquid state • Condensation Point – temperature at which a substance changes from a gaseous state to a liquid state • Sublimation – change from the solid state to the gaseous state • Deposition – change from the gaseous state to the solid state

6. Strand A – The Nature of Matter • Temperature – measure of the average kinetic energy of the particles of a substance. Scales used?

7. Strand A – The Nature of Matter • Waves • Crest – peak/highest point of wave • Trough – valley/lowest point of wave • Amplitude – distance the wave oscillates from its resting position. The larger the amplitude, the more energy carried by the wave. • Wavelength – the distance from one point on one wave to a corresponding point on an adjacent wave, ie. crest to crest, rp to rp, trough to trough • Resting Position

8. Strand A – The Nature of Matter • Element – simplest form of matter • Atom – smallest particle into which an element can be divided and still have properties of that element. • Compound/Molecule – Two or more elements that are combined. • Mixture – a combination of two or more substances that have not combined chemically

9. Strand A – The Nature of Matter • Subatomic Particles • Proton – positive charge – nucleus • Neutron – no charge – nucleus • Electron – negative charge – outside the nucleus (electron clouds) • Proton and neutrons have about the same mass. Electrons are significantly smaller. • An atom is identified by the number of protons in its nucleus

10. Strand A – The Nature of Matter • Isotopes – Isotopes are atoms of the same element that have different number of neutrons. • Hydrogen has one proton. • 0 neutron – protium • 1 neutron – deuterium • 2 neutrons – tritium

11. Strand B - Energy • Sound – energy carried by sound waves • Light – energy carried by light and other kinds of electromagnetic waves • Chemical – energy stored in chemical bonds • Thermal – Energy related to the temperature of a substance • Conduction, Convection, Radiation

12. Strand B - Energy • Conduction – transfer of heat from a warmer substance to a cooler substance (contact) • Convection – transfer of heat warmer fluid/gas rises and cooler sinks • Radiation – transfer of heat in the form of electromagnetic waves at random

13. Strand B – Energy • Law of Conservation of Energy – Energy cannot be created nor destroyed, it can only change form or be transferred • Kinetic Energy – energy an object has in motion • Potential Energy – stored energy an object has

14. Strand B - Energy • Energy from Sun (electromagnetic spectrum) • Energy inefficiency (heat loss) ie, lamp example • Heat flow  • Energy flow – sun  plants  animals  fossil fuels  heat

15. Scalars & Vectors • The motion of objects can be described by words - words such as distance, displacement, speed, velocity, and acceleration. These mathematical quantities which are used to describe the motion of objects can be divided into two categories. The quantity is either a scalar or a vector. These two categories can be distinguished from one another by their distinct definitions: • Scalars are quantities which are fully described by a magnitude alone. • Vectors are quantities which are fully described by both a magnitude and a direction.

16. Scalars & Vectors • Distance and speed are scalar quantities • Displacement and velocity are vector quantities. • Examples: While speed (like 30km/hr) is a scalar, velocity (30km/hr North) is a vector, consisting of a speed and a direction (north).

17. Distance/Displacement • Distance and displacement are two quantities which may seem to mean the same thing, yet they have distinctly different meanings and definitions. • Distance is a scalar quantity which refers to "how much ground an object has covered" during its motion. • Displacement is a vector quantity which refers to "how far out of place an object is"; it is the object's change in position.

18. Distance/Displacement Check • A student walks 4 meters East, 2 meters South, 4 meters West, and finally 2 meters North. 4 meters 2 meters 2 meters 4 meters

19. Distance/Displacement • Even though the student has walked a total distance of 12 meters, her displacement is 0 meters. During the course of her motion, she has "covered 12 meters of ground" (distance = 12 m). Yet, when she is finished walking, she is not "out of place" – i.e., there is no displacement for her motion (displacement = 0 m). Displacement, being a vector quantity, must give attention to direction. The 4 meters east is canceled by the 4 meters west; and the 2 meters south is canceled by the 2 meters north.

20. Distance/Displacement Check • The diagram below shows the position of a cross-country skier at various times. At each of the indicated times, the skier turns around and reverses the direction of travel. In other words, the skier moves from A to B to C to D. Use the diagram to determine the distance traveled by the skier and the resulting displacement during these three minutes. A B 40 m 40 m___ ‘ 100 m ‘ C D

21. Distance/Displacement • Seymour Action views soccer games from under the bleachers. He frequently paces back and forth to get the best view. The following diagram below shows several of Seymour's positions at various times. At each marked position, Seymour makes a "U-turn" and moves in the opposite direction. In other words, Seymour moves from position A to B to C to D. What is Seymour's resulting displacement and distance of travel?

22. Constant Speed • Moving objects don't always travel with erratic and changing speeds. Occasionally, an object will move at a steady rate with a constant speed. That is, the object will cover the same distance every regular interval of time. For instance, a cross-country runner might be running with a constant speed of 6 m/s in a straight line. If her speed is constant, then the distance traveled every second is the same. The runner would cover a distance of 6 meters every second. If you measured her position each second, you would notice that her position was changing by 6 meters each second. The following data tables depict both constant and changing speeds:

23. Instantaneous Speed • Since a moving object often changes its speed during its motion, it is common to distinguish between the average speed and the instantaneous speed. The distinction is as follows: • Instantaneous Speed - speed at any given instant in time. • Average Speed - average of all instantaneous speeds; found simply by a distance/time ratio.

24. Average Speed • As an object moves, it often undergoes changes in speed. For example, during an average trip to school, there are many changes in speed. Rather than the speedometer maintaining a steady reading, the needle constantly moves up and down to reflect the stopping and starting and the accelerating and decelerating. At one instant, the car may be moving at 50 mi/hr and at another instant, it may be stopped (i.e., 0 mi/hr). Yet during the course of the trip to school the person might average a speed of 25 mi/hr.

25. Average Speed • Average Speed = Distance/Time • Average Speed = 5 miles/.2 hour • Average Speed = 25 miles/hour • On the average, your car was moving with a speed of 25 miles per hour. During your trip, there may have been times that you were stopped and other times that your speedometer was reading 50 miles per hour; yet on the average you were moving with a speed of 25 miles per hour.

26. Velocity • Velocity is a vector quantity which refers to "the rate at which an object changes its position." • Imagine a person moving one step forward and one step back. Because the person always returns to the original position, the motion would never result in a change in position. Since velocity is defined as the rate at which the position changes, this motion results in zero velocity. • If a person in motion wishes to maximize his/her velocity, then that person must make every effort to maximize the amount that he/she is displaced from his/her original position. Every step must go into moving that person further from where he/she started. Heading in the opposite direction effectively begins to cancel whatever displacement there once was.

27. Terminal Velocity • The terminal velocity of an object falling toward the earth, in non-vacuum, is the speed at which the gravitational force is pulling downwards and an opposing force is faced by the resistance of air (resistance) pushing upwards. 9.8 m/s2

28. Acceleration • Acceleration is a vector quantity which is defined as "the rate at which an object changes its velocity." An object is accelerating if it is changing its velocity. • Sports announcers will occasionally say that a person is accelerating if he/she is moving fast. Yet acceleration has nothing to do with going fast. A person can be moving very fast, and still not be accelerating. Acceleration has to do with changing how fast an object is moving. If an object is not changing its velocity, then the object is not accelerating.

29. Strand C – Force and Motion • Non-contact forces – magnetism/gravity • Weight v. Mass • Series Circuit – connecting a circuit in a line • Parallel Circuit – divide the current among different devices

30. Strand C – Force and Motion • Friction – a force that resists motion • Sliding Friction – sliding • Static Friction – no motion • Rolling Friction – rolling • Air Resistance • Potential v. Kinetic? • Balanced v. Unbalanced Forces?

31. Force • A force is a push or pull. If an object accelerates (speeds up, slows down, or turns), a force is acting upon it. • The total force felt by an object is called the net force. • Some force are not visible (i.e. gravity, magnetism or earth’s gravitational field).

32. Forces • Balanced forces are two or more forces that cancel out each others effects and do not cause a change in motion. Net force equals zero. • Unbalanced forces exceed zero and therefore cause motion.

33. Newton’s First Law of Motion • Also know as Newton’s law of inertia. • “An object will remain at rest or move with constant velocity until it is acted upon by a net force” • Difficult to prove because of friction.

34. Friction • The unbalanced force that brings nearly everything to a stop. • The smoother the surface . . . • Static friction – prevents an object from moving when force is applied (i.e. pushing something heavy or walking). • Sliding friction – slows an object that can slide (i.e. skidding tires, shuffling shoes).

35. Newton’s Second Law of Motion • “An object acted upon by a net force will accelerate in the direction of the force according to the following equation: • Acceleration = net force/mass • a = F net/m or F net = ma • Force is measured in Newtons (N) • 1 N = 1 kg . m/s2

36. Newton’s Third Law • For every action, there is an equal and opposite reaction. • While driving down the road, an unfortunate bug strikes the windshield of a bug. Quite obviously, this is a case of Newton's third law of motion. The bug hit the bus and the windshield hit the bus. Which of the two forces is greater: the force on the bug or the force on the bus?

37. Strand D – Processes that Shape the Earth • Igneous Rocks – formed when magma or lava cools and becomes solid. • Sedimentary – formed when sediment is pressed and cemented • Metamorphic – formed when rock have been changed over time with high pressure and temperature

38. Strand D – Processes that Shape the Earth • Melting – hot temperatures deep inside Earth melt rocks, forming magma • Cooling and Hardening – Magma that rises from deep inside earth cools and hardens into rock (both above/below surface). • Weathering and Erosion – breaks apart existing rocks, forming sediment. Erosion moves sediment. • Compacting and Cementing – Pressure compacts; water between particles evaporates. • Heat and Pressure – melt and squeeze minerals changing the minerals or grain size.

39. Weathering Processes • Mechanical Weathering – process whereby rock physically break down into smaller pieces but do not change chemical composition. • Chemical Weathering – process whereby rock is broken down and chemical composition changes.

40. Agents of Mechanical Weathering • Ice Wedging – water seeps into cracks or joints in rocks and freeze. • Organic Activity – Roots of plants and animals burrowing. • Abrasion – collision of rocks with one another because of gravity, running water, or wind

41. Agents of Chemical Weathering • Hydrolysis – minerals chemically reacting with water. Minerals affected may be transported by water causing leaching. • Carbonation – minerals chemically reacting with carbonic acid (CO2 + H2O)

42. Agents of Chemical Weathering • Oxidation – metallic minerals chemically reacting with oxygen causing oxidation. • Acid Precipitation – CO2 + precipitation • Plant acids – weak acids produced by plants

43. Rates of Weathering • Rock Composition – Quartz is least affected; limestone is most affected. • Amount of Exposure – the more exposure the faster it will weather • Climate – Climates with much rainfall and freezing contribute most. Very hot or very cold = little weathering. Moist/humid = much weathering. • Topography – temperature/slope

44. Strand D – Processes that Shape the Earth • Weathering – breaks up rocks. • Mechanical • Ice Wedging • Release of Pressure • Abrasion (water, air, living things) • Plant action • Chemical • Oxidation • Acid Dissolution (Stalactite/stalagmite) (pneumonic)

45. The Water Cycle • The continuous movement of water from the earth’s atmosphere to the earth’s surface and back to the atmosphere again. • Also known as hydrologic cycle.

46. Water Cycle Processes • Evaporation – process by which liquid water changes into water vapor (86% from ocean; 14% from freshwater sources). • Transpiration – process by which plants give off water vapor into the atmosphere. • Evaportranspiration – combined processes of evaporation and transpiration.

47. Water Cycle Processes • Condensation – expanding/cooling causing cloud formation. • Precipitation – process by which water falls from clouds to the earth (i.e. rain, snow, sleet, and/or hail). About 75% of precipitation lands on the ocean.

48. Runoff – water that flows over the land into streams and rivers. • Groundwater – water that soaks deep in soil and rock

49. Water Conservation • Water uses and increased demand. • 90% of water used by cities/industries is returned as waste water. • Water Conservation • Finding other sources/Desalination (removing salts from ocean water).

50. Continental Drift • Theory stating that continents moved. • Proposed by Alfred Wegener. • Evidence included: • Identical fossil remains on the coast of South America and Africa • Age and type of rock on the coastline • Appalachian mountain chain • Glacier debris in Africa and South America