Blackville-Hilda Middle School
446 Country Club Road, Blackville, SC
Mr. Czar F. Mendoza
8th Grade - Earth Science
Measurement / Properties of Matter
1) An observation uses your senses, an instrument extends your senses; an inference (prediction) is a conclusion based on observations.
2) Classification – grouping by observable properties.
3) Graphing a direct relationship, as X-axis (independent variable) increases, Y-
axis (dependent variable) increases.
4) Graphing an indirect relationship, as X-axis increases, Y-axis decreases.
5) Dynamic equilibrium means balance.
6) As pressure increases, density increases.
7) As temperature increases, density decreases.
8) Volume of a regular object – Length X Width X Height. Volume of irregular object – Displacement of water.
9) Water expands when it freezes (other substances contract).
10) Water is most dense at 4oC, when it is a liquid
11) Anything with a density >1 will sink in water.
12. Porosity (the amount of empty space) does not depend on particle size (if you have the same shape & sorted – porosity is the same).
13. Permeability (the ability of a liquid to pass through) increases as particle size increases (rate increases as time decreases). If soil is highly permeable, water passes through very quickly.
14. Capillarity (the movement of a liquid upward against gravity) increases when particle size decreases.
Forces and Motion
15. Any kind of force is really just a push or a pull.
16. Magnetism is a type of force. A magnet might pull an object toward it or push it away.
17. Inertia is not a force. Anything with mass – or anything that has weight – automatically slows down because of that weight. This is inertia. The larger something is, the more inertia it has and the more force you need to make it move. An elephant has more inertia than a caterpillar, for instance.
18. Sir Isaac Newton was one of the first scientists to study gravity and force. Scientists still use his three laws today. The first one says that a body in motion is likely to stay in motion, while a body at rest will stay at rest. A kid playing soccer will probably keep playing. A kid watching movies will probably keep watching movies. The second law says that if a force acts upon a body, it will change the body’s speed or direction. If you kick a soccer ball, it’s going to change direction and speed. Finally, the third law says that for every force and action, there is an equal reaction. If you give that soccer ball a soft kick, it won’t go very far or fast. A big kick sends the soccer ball flying across the field.
19. Springs and elastic are also types of force. Push against them and they resist. They spring back with the same force you gave them.
Earth and The Universe
20 . The true shape of the Earth is an oblate spheroid (slightly flattened at the poles and slightly wider at the equator).
16.The best model of the Earth is a billiard ball – a perfectly smooth sphere.
17. Evidences that the Earth is round are: 1) “sinking ship” observation; 2) photographs from space; 3) Earth’s shadow on the Moon; 4) stars shift relative to the horizon as you move North and South 5) Eratosthenes’s measurements and 6) sunrise and sunset (sun hits tops of mountains first.).
18. A good map should have both scale and direction.
19. Latitude lines (parallels) measure distances North or South of the equator.
20. The universe began with a big explosion--"The Big Bang".
21.Our solar system is located on one of the outer arms of our Milky Way Galaxy.
22. All celestial objects appear to rise in the east and move west. (apparent motion)
23. An object speeding away from us will shift the light waves to the longer wavelength – red shift. Objects coming towards us, the light waves shifted to the shorter wavelength – blue shift due to the Doppler Effect.
24. Geocentric – Earth at center Heliocentric – Sun at center.
25.Proof of Heliocentric Theory – Coriolis Effect and Foucault Pendulum (appearance of change in swing direction).
26. Coriolis Effect deflects things to the right in the Northern Hemisphere
27. Moon orbits Earth in 27 1/3 days but we see a fill moon every 29 1/2 days.
28. Moon phases – new, crescent, quarter, gibbous, full (waxing then waning).
29. Light Right Returning – Waxing Moon; Light Left Leaving – Waning Moon
30.The moon has phases because it revolves around the earth (remember though that half is always lit).
31. The Moon rises later each day and sets later each day by 49 minutes – 12° per day. (360°/2)
32.Planets appear to go backwards (retrograde) as the earth passes them in space.
33. The closer something is the bigger it looks and the faster it appears to move.
34. The seasons are due to the tilt of the Earth’s axis (23 1/2°) in relation to the Sun.
35. Summer solstice is June 21st. The Sun rises 23 1/2° North of East and sets 23 1/2° North of t and is the longest day in New York State.
37. Winter solstice is December 21st. The Sun rises 23 1/2° South of East and sets 23 1/2° South of West and is the shortest day in New York State.
38. Equinoxes: March 21st; September 23rd. The sun rise due East and sets due West and has 39. hours of daylight everywhere.
40. Equator always has 12 hours of daylight.
41. The lower the altitude of the Sun the longer the shadow.
42. Aphelion - the point on an orbit farthest from the sun (A – away).
Perihelion - the point on an orbit closest to the sun.
43. Earth is closest to the sun in January and farthest in July.
44. The earth revolves counterclockwise around the sun (365 1/4 days).
45. The closer a planet is to the sun the higher
47. Vertical rays (overhead sun) can only occur between 23 1/2o N and 23 1/2o S.
48.The universe began with a big explosion--"The Big Bang".
49 Our solar system is located on one of the outer arms of our Milky Way Galaxy.
50. All celestial objects appear to rise in the east and move west. (apparent motion)3. An object 51.Moon orbits Earth in 27 1/3 days but we see a fill moon every 29 1/2 days.
52. Moon phases – new, crescent, quarter, gibbous, full (waxing then waning).
53. Light Right Returning – Waxing Moon; Light Left Leaving – Waning Moon
54. The moon has phases because it revolves around the earth (remember though that half is always lit).
55. The Moon rises later each day and sets later each day by 49 minutes – 12° per day. 15. The seasons are due to the tilt of the Earth’s axis (23 1/2°) in relation to the Sun.
56. The lower the altitude of the Sun the longer the shadow.
57. Aphelion - the point on an orbit farthest from the sun (A – away).
Perihelion - the point on an orbit closest to the sun.
58. Earth is closest to the sun in January and farthest in July.
59. The earth revolves counterclockwise around the sun (365 1/4 days).
60. The closer a planet is to the sun the higher
its velocity (the faster it orbits).
Types of Rocks/ Cycle
61. Sedimentary rocks may have flat layers - most likely to have fossils.
62.Igneous rock: cools very fast , glassy texture (no crystals); cools
fast (usually extrusive) - small crystals; slowly (usually intrusive) - large crystals.
63. Metamorphic: banded-distorted structure, re- crystallization.
Contact Metamorphism is caused by an igneous intrusion.
64. Mineral properties depend on internal arrangement of the atoms (color, streak, hardness, luster, cleavage & fracture)
65. There are 3 basic types of crustal plate boundaries: Divergent; Convergent; & Transform.
66.Evidence of plate tectonic theory is: 1) the fit of the continents; 2) the rock, mineral and fossil correlation; 3) evidence of ancient glaciers and tropical forests; and 4) alignment of the North Pole with the magnetism of different ages of rock.
67. Earthquakes and volcanoes usually occur along crustal plate boundaries.
68. Mid-ocean ridge - new crust being created-sea floor spreading.
69. Evidence of sea floor spreading is: 1) the reversal of magnetic polarity; and 2) the farther from the mid-ocean ridge, the older the rock (basalt).
70. Convection – movement due to differences in densities – works best in liquids & gas.
71. Convection currents in the mantle move plates.
72. Ridges create crust – area of divergence.
73Trenches destroy crust – subduction zone.
74. Uplift causes mountains.
75. Hot spots are not at plate boundaries.
76. Ocean crust is thin and made of basalt.
77. Continental crust is thick and made of granite.
78. Mountains form by uplift, folding and faulting.
P-waves (compression waves) are faster than S-waves (shear waves).
79. P-waves - can pass through solids & liquids -- S-waves can pass through solids only.
80. You need at least 3 seismometer stations to plot earthquake.
81. The focus is the underground position of the earthquake; the epicenter is the point on the surface directly above the focus.
82. Scientists infer earth’s properties from earthquakes (seismic data) and meteorites.
83. Water affects the soil and can cause weathering
84. Weathering is breaking things down, Erosion is moving them and Deposition is dropping them.
85. Physical weathering occurs mostly in cold, humid climates (good for frost wedging).
86. Chemical weathering occurs mostly in warm, humid climates.
87. When a rock is broken into smaller pieces, surface area increases and weathering rate increases.
88. Gravity is the force behind all erosion.
89. Running water is the number one agent of erosion.
90. Stream velocity depends on slope and discharge.
91. Stream velocity is fastest on the outside of meander bend (curve) and causes
erosion, slower at inside edge and has deposition occurring.
Waves and Energy/ Energy transformation
92. Infrared has a long wavelength; Visible light has a short wavelength (more intense).
93. Carbon dioxide (CO2) and water vapor absorb infrared radiation.
94. Energy moves from source to sink: high to low.
95. Potential Energy – stored energy.
96. Kinetic Energy – energy of motion.
97. Black and rough surfaces are the best absorbers and radiates.
98. Good absorbers of radiation are good radiators.
99. Land heats up faster than water, also cools faster.
100. Water bodies moderate temperature (smaller temperature range).
101. Boiling: liquid water changing to water vapor (steam) – add heat.
102. Condensation: water vapor changing to liquid water – remove heat.
103.Conduction – molecule to molecule - works best in solids.
104. Radiation – movement by waves – no medium necessary.
105. Convection – movement due to differences in densities – works best in liquids & gas.
106. There is NO temperature change at a phase change.
107. As temperature increases, air pressure decreases.
108. As moisture increases, pressure decreases.
109. Air pressure decreases with altitude.
110. Air cools and expands as it rises, warms as it falls.
7th Grade - Earth Science
An observation uses your senses, an instrument extends your senses; an inference (prediction) is a conclusion based on observations.
In experiment, you have to identify the different variables
Dependent variable- the observable effect in an experiment
Independent variable- the manipulated cause /treatment in an experiment
constant- “ does not change”
Measurement / Properties of Matter7) Classification – grouping by observable properties.
Graphing a direct relationship, as X-axis (independent variable) increases, Y-
Graphing an indirect relationship, as X-axis increases, Y-axis decreases.
Dynamic equilibrium means balance.
As pressure increases, density increases.
As temperature increases, density decreases.
Volume of a regular object – Length X Width X Height. Volume of irregular object – Displacement of water.
Water expands when it freezes (other substances contract).
Water is most dense at 4oC, when it is a liquid
Anything with a density >1 will sink in water.
Porosity (the amount of empty space) does not depend on particle size (if you have the same shape & sorted – porosity is the same).
Permeability (the ability of a liquid to pass through) increases as particle size increases (rate increases as time decreases). If soil is highly permeable, water passes through very quickly.
Capillarity (the movement of a liquid upward against gravity) increases when particle size decreases.
Atoms, Elements and Compounds
A substance made up of one kind of atom is an element.
2.Gold is an element because it only contains gold atoms.
3. Water is not an element because it contains hydrogen and oxygen atoms, it is a compound 4.The atomic number is the number of protons in the atom’s nucleus.
5. Scientists have identified 92 elements that occur naturally.
6.Over three-fourths of the natural elements are METALS. The heaviest natural element is the metal uranium.
7.Hydrogen and helium are the most common elements in the Universe. Stars are made almost entirely of these elements. The most common elements in the Earth’s crust are oxygen and silicon.
8. Elements in the same group (column) have similar properties. The properties change gradually along periods (rows) in the table—elements on the left are metals, elements on the right are nonmetals.
In Ancient Greece a man named Democritus figured out that every single thing in the universe must be made up of tiny particles that can’t be cut anymore. He called these particles “atoms”, which in Greek means “uncuttable”.
• An atom is the smallest particle of an element still having the same chemical properties of the element.
• The particles smaller then atom are called subatomic particles.
• At the center of the atom is a core called a nucleus, which is made up of these subatomic particles called protons and neutrons. Whizzing around the nucleus at incredible speeds are tiny particles called electrons.
• Electrons are extremely small. You could fit 2,000 of them into one proton.
• There are over 100 different kinds of atoms.
• By combining theses atoms in different ways, we can make anything in the universe.
• Atoms are so tiny that they can’t be seen, even with the most powerful microscope.
Even though protons and neutrons make up the nucleus of an atom, most of the nucleus is empty space.
When atoms combine together they form molecules.
Cell is the smallest unit in the living organism that is capable of integrating the essential life processes.
Cells can be separated into two major groups— prokaryotes, cells whose DNA is not segregated within a well-defined nucleus surrounded by a membranous nuclear envelope, and eukaryotes , those with a membrane-enveloped nucleus. The bacteria (kingdom Monera ) are prokaryotes.
All organisms other than bacteria consists of one or more eukaryotic cells.
All cells share a number of common properties; they store information in genes made of DNA; they use proteins as their main structural material
Each eukaryotic cell has a repeating set of events that make up the life of every cell, called the cell cycle.
Interphase, Mitosis, Cytokinesis
-The interphase continuum of stages, G1, S, and G2, begins the process in which the cell grows and matures (G1), followed by the S phase in which the DNA is copied.
-Finally, the G2 phase is when the cell prepares for division.
-Mitosis occurs when the nucleus of the cell divides into two identical nuclei with the same number and type of chromosomes
-cytokinesis when the cytoplasm, for both plant and animal cells, divides, thus creating two daughter cells that are genetically equal and approximately identical in size.
Asexual reproduction guarantees that the offspring will be both genetically and structurally identical to each other and their parent.
Asexual reproduction produces offspring in four distinct methods:
• Budding is when offspring begin as outgrowths or “buds” of the parent. e sponges.
• Fragmentation is common in cnidarians and some worms, and occurs when a piece or pieces of an organism are cut off or broken off from the main body. • Binary fission is a combination of mitosis and cytokinesis because an organism simply divides into two organisms, especially common in flatworms.
39. Ecosystem- consists of a living community, its environment, and all their interactions. 2.community is a group of animals, plants, and microorganisms that live together in the same area, or habitat. Its environment includes sunlight, rainfall, and shelter.
3.Coral reefs have high biodiversity because they contain large numbers of different species. 4.Deserts have low biodiversity because they have far fewer species. Humans have reduced biodiversity in many ecosystems by harmful activities, such as overfishing.
5.Ecosystems are continually changing, often very slowly, sometimes very fast. A forest fire, for example, can wipe out an ecosystem without warning.
6.FOOD CHAIN - In any ecosystem, species eat and are eaten by other species. A food chain is a simple pathway that connects up to six species by what they eat. It describes the route followed by energy and nutrients as they are passed from organism to organism.
7. FOOD WEB - The interconnected network of food chains in an ecosystem Predators are fewer in number than prey because they are higher up the food chain. In a food chain, an organism passes on only part of the energy it receives from food. With less energy, each level in a food chain supports fewer individuals than the one below it.
8. Organisms take chemical nutrients, such as carbon, nitrogen, and water, from their surroundings.
9. Certain fungi and bacteria, called decomposers, play a key role. They break down, or decompose, the remains of dead organisms. This releases carbon dioxide back into the air, where it can be reused by plants.
10. Plants take up nitrogen-containing chemicals, called nitrates, from the soil. Animals obtain nitrogen by eating plants, or animals that eat plants.
11. Bacteria release the nitrogen in dead plant and animal matter, allowing it to be returned to the soil. Nitrogen is an important part of proteins that cells need to survive.
12. Most rainwater flows to the sea along rivers, but some is taken up by plant roots.
13. Water evaporates from plant leaves back into the air. Like water evaporated from the sea, it rises into the air, and falls as rain.