8th Grade Physical Science Final Study Guide Name ______
1. What is the only method to break down compounds? _Chemical Change
2. Which process causes drops of water to appear on the outside of a glass of juice on a warm day?Condensation
3. Which kind of change adds energy to a substance? Chemical Change
4. Which type of elements are all poor conductors of heat and electric current? Non-metal
5. What is a pure substance that can not be separated into simpler substance by physical or chemical means called? __Element______
6. The substances that dissolve in a solvent are called __Solute______.
7. All atoms of the same element have the same atomic __Weight______, which can be found on the periodic table.
8. Which metals are only found in nature combined with other elements because of their highly reactive nature? ___Alkali Metals______
9. An object’s change in position over a period of time is called __Motion______.
10. The speed of an object in a particular direction is its ___Velocity______.
11. If a driver’s acceleration is positive, then the driver’s velocity is ______.
12. A _Force______is a push or pull on an object.
13. The measure of the gravitational force exerted on an object is _Weight______.
14. A falling object will stop accelerating when air resistance exactly matches the downward force of gravity, which is ___Terminal Velocity______.
15. The tendency of all objects to resist any change in motion is called __Inertia______.
16. Which type of lever places the load between the input force and the fulcrum? _2nd degree______
17. Which type of pulley is attached to something so it does not move? ___Fixed______
18. The work you do on a machine such as turning a screwdriver is called __Work Input______.
19. A bar that pivots on a fulcrum is a __Lever______.
20. ______is the transfer of energy between two objects with different temperatures.
21. Differences in temperatures in liquids and gases result in __Convection______currents.
22. ___Radiation______is the way that the energy from the sun is transferred to the Earth.
23. When ice changes to liquid it______Absorbs______energy.
24. When vapor condenses to a liquid, energy is ___Released______.
25. The particles in a __Solid______do not overcome the attraction between them, so they vibrate in place.
26. The distance between two rarefactions that are next to each other is the___Wavelength______of a wave.
27. The bouncing back of a ray of light, sound or heat when they ray hits a surface that it does not go through is called ____Reflection______.
28. If a barrier or opening is the same size or smaller than the wavelength of an approaching wave, there will be a __Greater______amount of diffraction.
29. When two waves meet and cancel each other out, _Destructive Interference______occurs.
30. The maximum distance a wave vibrates from its rest position is called its____Amplitude______.
31. When a wave curves or bends around a barrier, ___Diffraction______occurs.
32. The frequency of a sound wave determines the ___Pitch______of the sound.
33. The particles of the medium in a ___longitudinal______wave vibrate back and forth along the path of the wave.
34. __Absorption______is the transfer of energy carried by light waves to particles of matter.
35. An electromagnetic wave that can cause sunburn is __radiation______.
36. Light you can see is called ______Visible Light______.
37. The opposition to the flow of electric charges is ____Resistance______.
38. Lightning is a form of ______Electric Discharge______.
39. A(n) ___Electric Field______is the region around a charged object where an electric force is present.
40. As resistance goes up, current goes ______down______.
41. An object’s __Mass______would be the same on the moon as it is on Earth, but not its weight.
42. If you poured three liquids (that don’t mix completely) into a beaker, how could you tell which one is the most dense? It’s on the bottom
43. The explosion of fireworks is an example of what type of change? Chemical Change
44. Why are chemical properties harder to observe than physical properties? They are at the molecular level
45. Ground flour is an example of what type of change? Physical
46. Which unit would be best for describing the volume of mercury (liquid) used in an experiment? mL
47. The motion of a 150 g ball is more difficult to change than the motion of a 50 g ball because it has more__Mass____.
48. Which physical property of matter describes the relationship between mass and volume?
49. What property of matter (inertia, mass, volume, or weight) is demonstrated by the fact that you cannot fit any more books onto a bookshelf that is already filled?
50. To change the mass of an object, what do you add or take away? Matter
51. How are the particles arranged in a solid?
52. Describe how the particles in a gas move. Quickly & Freely
53. How do the particles of water that evaporate from an open container differ from the particles that remain? They are a gas.
54. The melting point of salt is the same as its ___Freezing______point.
55. The particles that make up different types of matter do not move at the _same______speed.
56. Boiling point, melting point, and density are some of an element’s __Physical ______properties.
57. What is formed when particles of two or more substances are distributed evenly among each other? Solution
58. How is a compound different from a mixture? The molecules are chemically combined.
59. How could a sugar cube be dissolved more quickly in water? Crushed, increase temperature
60. An unidentified substance is a good conductor of electricity, shiny and malleable. It is probably a(n) Metal______.
61. A(n) _Metalloid______is an element that has the properties of both metals and nonmetals.
62. A substance in which a solute dissolves is a(n) __Solvent______.
63. Why is muddy water not a solution? Because the dirt/mud can settle down.
64. What is a pure substance made of two or more elements that are chemically combined? Compound
65. How would you describe the size, density, and overall charge of a nucleus? Largest part of the atom, dense, Positive charge
66. What is the smallest particle into which an element can be divided and still be the same substance? Atom
67. An atom of carbon with 6 protons, 6 electrons, and 6 neutrons would have a mass number of __12______.
68. In an atom, which particle has the least mass? Electron
69. A hydrogen atom with one proton in its nucleus has a(n) __Atomic Number______of one.
70. Periodic law states that _Repeating chemical & physical properties of elements change periodically with the elements’ atomic numbers.
71. The elements to the right of the zigzag line on the period table are called __Non- Metals______.
72. Most metals are __Solid______at room temperature.
73. The vertical column of elements on the periodic table is called a(n) _Group______.
74. What are most of the elements in the periodic table – metals /nonmetals/metalloids? Metals
75. What are the left-to-right rows on the periodic table called? Period
76. An explosive breaking rocks in a mine is an example of chemical ______breaking.
77. What happens between chemical bonds when a new substance forms during a chemical reaction? Break & Rearrange.
78. A calcium carbonate molecule has 1 calcium (Ca) atom, 3 oxygen (O) atoms, and 1 carbon (C) atom. What is the chemical formula for calcium carbonate? CaCO3
79. State the law of conservation of energy. Energy is neither created nor lost in a closed environment
80. How many atoms are represented in the formula CaCO3? 5
81. In a chemical reaction, atoms are never/always gained or lost. Never
82. What is the reference point of an SUV driving past a jogger at a relative speed of 15 m/s compared to the jogger? Jogger
83. What kind of force is acting on a swing hanging still from the porch roof? ___Balanced Force______
84. The main difference between speed and velocity is __Velocity is speed in a certain direction.______.
85. Velocity change vs. time best represents ___Acceleration______as presented on a graph.
86. The combination of all __Forces______acting on an object best determines the net force when more than one force is acting on an object.
87. Net forces that equal 0 N are considered __Balanced______.
88. __Unbalanced ______Forces______always cause a change in speed, direction, or both.
89. ______Friction______is a force that opposes motion between two surfaces that are in contact.
90. Car tires moving a car forward are an example of when _Friction______is helpful.
91. Pouring sand on ice is/is not a way to reduce friction. Is Not
92. True/False: All matter has mass; all mass is affected by gravity. True
93. As the distance between two objects increases, the force of gravity between them _Decreases______.
94. True/False: Mass is described as remaining constant. False
95. Gravitational pull is greater/less between two objects that have greater masses.Greater
96. You would add/subtract the following to determine the net force:10 N north & 5 N south. What is the answer?Subtract
97. The measure of the amount of matter is _Mass______.
98. Average speed is calculated by dividing _Total ______Distance_____ by _Total ______Time______.
99. When an object goes straight at a constant speed, there is no _Acceleration______.
100. A student weighs 70 N on the moon (Moon’s gravity = 1/6 Earth’s gravity). What does he weigh on earth? 420N
101. Gravitational force is related to mass and distance is the law of __Universal Gravitation______.
102. If you have the starting velocity, final velocity and the time it takes to change the velocity, you can calculate an object’s __Average Velocity______.
103. The force of __Gravity______is greater between two objects that have greater masses.
104. Mass is a measure of the amount of ____Matter______in an object.
105. If a baseball and a cannonball are dropped from the same height at the same time, which ball will hit the ground first? Baseball/Cannonball/Both at same time Both at the same time
106. Projectiles accelerate in which direction? ___Downward______
107. The reaction force of a chair you are sitting on is greater than/less than/equal to your weight. Equal to
108. When a bowling ball collides with a bowling pin, the momentum of the ball increases/decreases as the velocity increases/decreases? Decreases / Decreases
109. If a moving boxcar gently collides with a boxcar at rest and the two boxcars move together, their combined momentum will be greater than/less than/equal to the original momentum of the moving boxcar. Greater than
110. If an action force is a cue ball hitting a billiard ball, then the reaction force is __Billiard ball reacts against the cue ball
111. The path of a crate sliding along flat ground is/is not an example of projectile motion. Is Not
112. If dropped at the same time from the same height, a tennis ball/a solid rubber ball/a solid steel ball would hit the ground first. (Assume no air resistance) The same time
113. An empty shopping cart, pushed with a light force has more or less acceleration than a full shopping cart pushed with a light force. Less Acceleration
114. A crumpled piece of paper hits the ground before a flat sheet of paper because there is more _Air Resistance______on the flat sheet of paper.
115. _Gravity______causes the path of a ball thrown horizontally to curve downward.
116. A pitched baseball gets its horizontal motion from __the hand that exerts a force on the ball___.
117. Which of Newton’s Laws best describes an ice skater at rest pushing against a sled at rest causing both the skater and sled to move away from each other with different accelerations? 3rd Law (For every action there is an equal and opposite reaction)
118. Which of Newton’s Laws best describes a sled sliding on a flat, icy surface with a constant velocity? 1st Law – On object in motion tends to stay in motion at a constant speed and in the same direction.
119. What device makes work easier: changing the size or direction of the force? Machine
120. A school crossing guard raising a stop sign that weighs 10 N is an example of _Work______being done on an object.
121. If a barbell weighs 160 N, what other information do you need to calculate how much work it takes to lift it? The distance it was lifted.
122. How does a ramp make lifting a heavy object easier? By increasing the distance over which the work was done.
123. The work output of a machine is always less than the work input, and the missing work is used to overcome the __Friction______created by the machine.
124. A block and tackle pulley is an example of a _Compound Machine______.
125. When a machine increases the size of the force exerted, the distance must __Increase______.
126. In order to increase the mechanical advantage of a first-class lever, the __Fulcrum______ should be moved closer to the load.
127. A doorknob is an example what type of simple machine? Wheel & Axle
128. Water boils at 212°F, which is equivalent to ____0______°C.
129. The hot air that you see rising from the pavement on a summer day is an example of __Convection______.
130. The transfer of thermal energy through a substance by direct contact is called _Conduction______.
131. When a substance changes state, what happens to the substance? It changes from one form to another
132. If the particles of two substances have the same average kinetic energy, then the substances have __The same_____ temperatures.
133. The glass of a window pane feels cooler to the touch than the wood frame surrounding the glass. This is because wood is a better _Insulator______ than glass.
134. In which state of matter does water have the lowest average kinetic energy? Solid
135. In which state of matter do particles move fastest and with little effect on each other? Gas
136. What happens to a substance’s temperature during a change of state? Changes
137. If each has the same temperature, which object has the most thermal energy? large pan of water/tub of water/ small cup of water/small bowl of water Tub of water