1. CRCT Practice

2. S8P1. Students will examine the scientific view of the nature of matter.

3. a. Distinguish between atoms and molecules.

4. Atoms – are the basic building block of all matter.
Each kind of atom is an element – a pure substance that cannot be broken down into simpler substances.

5. There are 117 confirmed elements
There are 117 confirmed elements. 90 of these are found in nature and the rest are synthetic (man made)

6. Mass Location Charge Proton Nucleus + 1 amu Neutron Electron
Electron
Electron Cloud -
Less than 1 amu

7. Atomic Number – describes the number of protons in the nucleus of the atom.
Atomic Mass – equal to the number of protons plus the number of neutrons in the atom.

8. Neutral Atom – occurs when electrons equal protons.

9. A molecule is the smallest unit of a compound that has all the properties of the compound.

10. A subscript is a small number that tells you the number of atoms of each element in the substance.

11. b. Describe the difference between pure substances (elements and compounds) and mixtures.

12. An element is an pure substance that cannot be broken down into simpler substances by ordinary chemical means.
Compounds are pure substances that are created when atoms are chemically combined.

13. Mixtures form when two or more substances combine without joining together chemically.
Heterogeneous mixtures – look different throughout
Homogeneous mixtures – look the same throughout

14. c. Describe the movement of particles in solids, liquids, gases, and plasmas states.

15. A state of matter is the physical form in which matter exists.

16. A solid is a substance with
definite shape and volume
Particles are densely packed
Energy binding the particles is very strong

17. A liquid is a substance that
Has no definite shape
Has definite volume
Particles are less densely packed and can flow around each other
Energy binding the particles is strong

18. A gas is a substance that has
NO definite shape
No definite volume
The particle arrangement is far apart
The binding energy is very weak.

19. Plasma is a state of matter that forms when temperatures are high enough to remove electrons from their atoms.

20. d. Distinguish between physical and chemical properties of matter as physical (i.e., density, melting point, boiling point) or chemical (i.e., reactivity, combustibility).

21. Physical Properties are characteristics that can be observed or measured without changing the identity.

22. Chemical Properties are characteristics that describes how a substance will interact with other substances during a chemical reaction.

23. e. Distinguish between changes in matter as physical (i. e
e. Distinguish between changes in matter as physical (i.e., physical change) or chemical (development of a gas, formation of precipitate, and change in color).

24. Physical Change – alters the physical properties of a substance without changing the identity of the substance.
Chemical Change – occurs when a substance is changed into a new substance with different properties.

25. f. Recognize that there are more than 100 elements and some have similar properties as shown on the Periodic Table of Elements.

26. The periodic table is a chart that organizes the information about all of the known elements according to their properties.

27. Periods – Horizontal Rows (7)
Groups – Vertical Columns (18)

28. Elements in the same group have similar properties.
These properties are a result of their identical valence electron numbers.

29. Reactivity – describes how likely an element is to form bonds with other elements.

30. Most chemically active are group 1 elements
Most chemically active are group 1 elements. (Due to their 1 valence electron)
Group 18 (Noble Gases) are inert. This means they cannot not form bonds with other elements because they are chemically stable.

31. Elements on the left are metals (except H)
Elements on the right are nonmetals
Elements along the stair step line are metalloids

32. g. Identify and demonstrate the Law of Conservation of Matter.

33. The law of conservation of matter states that during a chemical reaction, matter cannot be created or destroyed.
Mass of the reactant equals the mass of the product

34. A coefficient is a number that can show how many molecules of a compound are present.

35. S8P2. Students will be familiar with the forms and transformations of energy.

36. a. Explain energy transformation in terms of the Law of Conservation of Energy.

37. Law of Conservation of Energy – Energy is not created or destroyed but can be transferred.

38. Examples of Energy Transformations:
Plants convert electromagnetic energy from the sun into chemical energy through photosynthesis

39. Eating vegetables allows your body to convert stored chemical energy into thermal energy to maintain body temp and mechanical to allow you to move

40. The sun converts nuclear energy into electromagnetic and thermal energy

41. b. Explain the relationship between potential and kinetic energy.

42. Kinetic energy – the energy of “motion”
Depends on mass and velocity
Greater the mass; Greater the KE
Greater the velocity; Greater the KE

43. Potential energy – stored energy
Ex.
Chemical Potential – energy stored in chemical bonds

44. Elastic Potential – energy stored in stretched or spring objects
Gravitational Potential – energy stored in objects above Earth’s surface

45. c. Compare and contrast the different forms of energy (heat, light, electricity, mechanical motion, sound) and their characteristics.

46. Each form of energy has its own characteristics.
Mechanical – Associated with energy of motion (kinetic).
Thermal Energy – total amount of energy in all the particles

47. Heat – thermal energy that’s transferred from high to low temperature
Chemical Energy – energy stored in chemical bonds

48. Electrical Energy – energy that results from moving charges
Electromagnetic – energy resulting from the motion of atoms
Light, X-rays, Microwaves, UV

49. Sound Energy – energy given off by a vibrating object
Nuclear Energy – energy stored in the nucleus of an atom
Released through Fission and Fusion

50. d. Describe how heat can be transferred through matter by the collisions of atoms (conduction) or through space (radiation). In a liquid or gas, currents will facilitate the transfer of heat (convection).

51. Temperature is the measure of the average kinetic energy of particles.

52. Heat is the transfer of thermal energy between objects at different temperatures
Flows from higher temperature to lower temperature

53. Heat can be transferred through matter in all three phases and can be transferred through a vacuum (empty space).

54. Conduction – Heat is transferred through solids and liquids by direct contact of the particles.
Convection – Heat is transferred through fluids (liquids and gases) by currents.

55. Radiation – transfer of heat without matter – uses electromagnetic waves.

56. S8P3. Students will investigate relationship between force, mass, and the motion of objects.

57. a. Determine the relationship between velocity and acceleration.

58. Force – a push or a pull sometimes resulting in motion.
Reference Point – a generally stationary point such as a tree, or street sign that allows you to define the motion of an object in terms of speed, position, and direction.

59. Speed – how fast the object moves.
Speed = distance / time
Units – m/s
Distance/Time Graph:
Distance on the Y-axis
Time on the X-axis

60. Velocity – speed of the object in a given direction.
Velocity changes when the speed or the direction of an object changes.

61. Acceleration – the rate at which velocity changes.
Acceleration changes if the speed or its direction changes.
Formula:
a = vf – vi t
Units – m/s/s

62. b. Demonstrate the effect of balanced and unbalanced forces on an object in terms of gravity, inertia, and friction.

63. Net Force – the sum of the forces acting on an object.

64. Balanced Forces –
equal forces acting in opposite direction
Net force equals zero

65. Unbalanced Forces
Net force is greater than zero
Object moves in the direction of the greater force
Can cause a change in the motion of an object

66. Inertia – an object’s resistance to a change in motion.
Greater Mass – Greater Inertia

67. Friction – the force that opposes the motion of an object
Static – no motion
Sliding – objects sliding past each other

68. Rolling – objects rolling past each other
Fluid – friction from a liquid or gas

69. Gravity – force of attraction between all objects.
Depends on Mass and Distance

70. c. Demonstrate the effect of simple machines (lever, inclined plane, pulley, wedge, screw, and wheel and axle) on work.

71. Work – when a force is applied to an object and the object moves in the direction of the force.
W = F x d
Only occurs when the object moves in the direction of the force

72. Machines – makes work easier by:
Multiplying effort force
Changing direction of force
Increasing Distance

73. 6 Simple Machine
Levers
Pulleys
Wheel and Axle
Inclined Plane
Wedges
Screws

74. Lever – a bar that is free to pivot about a fixed point
Force Applied – Effort Force
Resistance – Load
3 classes of Levers

75. Pulley – a rope or chain wrapped around a wheel
Makes work easier by changing direction of the force
Block and Tackle pulleys multiply effort force

76. Wheel and Axle – consists of two wheels of different sizes.
Larger – Wheel
Smaller – Axle
Makes work easier by increasing the effort force

77. Incline Plane – a straight, slanted surface
Makes work easier allowing you to use less effort over a greater distance

78. Wedges – an inclined plane that is wider or thicker at one end than the other
Makes work easier by changing the direction of the effort force

79. Screw – an inclined plane that is wrapped around a cylinder
Makes work easier by increasing the number the threads

80. S8P4. Students will explore the wave nature of sound and electromagnetic radiation.

81. a. Identify the characteristics of electromagnetic and mechanical waves.

82. Wave – any disturbance that transfers energy through matter or space.
Medium – the material through which waves can travel

83. Mechanical Wave - a wave that needs a medium
Transverse Wave – a wave that transfers energy in a direction that is perpendicular to its medium.
Longitudinal Wave –particles move back and forth.

84. Electromagnetic Wave – A wave that doesn’t need a medium through which to travel

85. b. Describe how the behavior of light waves is manipulated causing reflection, refraction diffraction, and absorption.

86. When a wave hits an obstacle, passes from one medium to another, or hits another wave, it is possible that it will change speed, direction, or shape.

87. Reflection – occurs when a wave bounces back after striking a barrier.
Sound Reflection = Echo
Light Reflection in mirror allows you to see yourself

88. Refraction - the bending of a wave as it passes at an angle from one medium to another.
Light Refracts (bends)
Enters a lens
Enters a prism
Enters water from air (bent pencil)

89. Diffraction – refers to the bending, spreading, and interference of waves when thy go through a narrow opening.
When waves pass through a slit, a pattern of ripples forms in all directions

90. Interference – when two waves collide
Constructive – crest hits crest
Destructive – trough hits trough

91. Transmission – passing of waves through a medium
Transparent– most of light transmits through the material
Windows, Plastic Wrap

92. Absorption -disappearance of an EM wave into a medium
Opposite of Reflection

93. You see different colors due to reflection and absorption
An apple looks red b/c all colors but red are absorbed and red is reflected back to your eye

94. c. Explain how the human eye sees objects and colors in terms of wavelengths.

95. Your ability to see involves the reflection of light.

96. The Eye
Cornea – transparent material helps move light into the eye
Pupil – small hole that adjusts size in order to control amount of light entering

97. Lens – responsible for focusing light
Retina – where the light rays focus the image
Optic Nerve – relays information about image to brain

98. Electromagnetic Spectrum – collection of all EM frequencies
Radio waves – longest wavelength, lowest frequency
Used in AM & FM broadcasting

99. Microwaves – More energy than radio waves.
Radar
Infrared Light – associated with heat.

100. Visible Light – only part of spectrum that you can see
Longest Wavelength is Red
Shortest Wavelength is Violet
You see color because of the way light interacts with an object.

101. Ultraviolet Light – have a higher frequency than visible light
Can cause reactions: tan the skin, too much may lead to skin cancer

102. X-rays – can travel through soft tissue, such as skin, but not through hard bone.
Gamma Rays – have the shortest waves and highest frequencies
Most Energy on Spectrum

103. d. Describe how the behavior of waves is affected by medium (such as air, water, solids).

104. In order to see any object, it must give off light.
Luminous – objects that emit their own light

105. Illuminated – objects that reflect light to your eyes
Amount of reflected light depends on the surface. (Smooth reflects more light than rough surfaces.)

106. Law of Reflection – the angle at which any wave strikes a reflecting surface is equal to the angle at which the wave is reflected

107. Transparent – material that permits light to pass through
Translucent – material transmits some light
Opaque – allow no light to pass through
(Wood, Carpet)

108. e. Relate the properties of sound to everyday experiences.

109. Sound is a form of energy produced by vibrating objects.
Mechanical Wave (needs a medium)
Longitudinal Wave (moves back and forth)

110. Pitch – highness or lowness of a sound
Frequency – number of waves that pass a fixed point in a given time period

111. Human Ear
Outer – collects sounds
Middle – transfers energy into inner ear by vibrating the 3 small bones
Inner – cochlea stimulates nerve cells and sends signal to auditory nerve.

112. Doppler Effect – change in the frequency of a sound due to a moving sound source or a moving listener
Resonance – ability of objects to pick up the frequency of a nearby object

113. f. Diagram the parts of the wave and explain how the parts are affected by changes in amplitude and pitch.

114. Amplitude – is a measure of wave energy.
Height of the wave

115. Wavelength – the distance between two successive points on a wave
Crest to Crest or
Trough to Trough
Compression to Compression
Rarefaction to Rarefaction

116. Frequency – the number of waves produced in a given amount of time
Higher Frequency = Shorter Wavelength
Lower Frequency = Longer Wavelength
Unit = Hertz (Hz)

117. Pitch – refers to the highness or lowness of a sound.
Determined by the frequency of the sound.
Low Pitch = Low Frequency
High Pitch = High Frequency

118. Wave Speed – speed at which a wave travels
Speed = wavelength x frequency

119. Affected by :
Medium through which wave is traveling.
Mechanical Waves travel fastest through solids
Electromagnetic Waves travel at the same speed

120. S8P5. Students will recognize characteristics of gravity, electricity, and magnetism as major kinds of forces acting in nature.

121. a. Recognize that every object exerts gravitational force on every other object and that the force exerted depends on how much mass the objects have and how far apart they are.

122. Gravity – an attractive force that works to pull objects together.
Law of Universal Gravitation – the force of gravity acts between all objects in the universe

123. Gravitational Force depends on:
Mass – amount of matter
Distance
Greater the Mass; Greater the gravitational attraction
Closer Distance; Greater gravitational force

124. Newton’s 1st Law of Motion – an object in motion stays in motion, an object at rest stays at rest unless an unbalanced forces act on it.

125. Inertia – tendency of an object to resist a change in its motion.
Greater Mass; Greater Inertia

126. The moon is able to continuously orbit Earth because the Moon’s inertia and Earth’s gravity are balanced.

127. b. Demonstrate the advantages and disadvantages of series and parallel circuits and how they transfer energy.

128. Electrical Energy is produced by the movement and distribution of charged particles from the atom.

129. Electric Current – the flow of electric charges.
Unit – Ampere (A)

130. Potential Difference (aka Voltage) – results from the differences in electrical charges in two locations.
Unit = Volts (V)

131. Circuits – a path through which electricity can flow.
Energy Source – “push” charges through circuit (battery – greater voltage; greater “push”)

132. Load – operates using electrical energy (“light bulbs”)
Conductors (Wire) – material that allows electrical energy to flow easily

133. Series Circuit – a circuit that provides one possible path for the e- to flow
One bulb burn out – all bulbs burn out

134. All loads share the same energy source
More bulbs added; dimmer lights get

135. Parallel Circuit – offers more than one path for the flow of electricity.
Each load has its own closed pathway
If one bulb burns out; the others are unaffected
Loads do not share a current.

136. c. Investigate and explain that electric currents and magnets can exert force on each other.

137. Magnetic Force – a push or a pull that is exerted by a magnet
Magnets have 2 poles – north and a south pole
Cutting a magnet in half gives you two smaller magnets with a N & S pole.

138. Magnetic Field – area surrounding a magnet in which the magnetic force exists
Lines extend from one pole of the magnet to the other

139. Electromagnetism – production of a magnetic field by an electric current
Electric current flows through a coil of wire a magnetic field is produced similar to a bar magnet.

140. Electromagnet – magnet that is made by passing an electric current through a coil of wire wrapped around an iron core.

141. Usefulness of electromagnets:
Temporary – they can be turned off and on
Strength of magnet can be increased
Increase strength of current
Add more coils
Increase size of core

142. Electric Motor – transforms electrical energy into mechanical
Generator – transforms mechanical energy into electrical