Sunday, June 2, 2013

7 th Grade Science Final Exam Review Notes

7th Grade Science Final Exam Review 1. All sound waves are caused by something vibrating. 2. A physical change is a reaction that does change the identity of the product. Example: when water freezes it goes from liquid to solid state, but the original composition is still water. 3. The identity of the composition is conserved in a physical change. 4. A chemical change is when the original composition of the components involved changes into something else. Example: when metal is exposed to water or oxygen, it oxidizes and rust is created. The product rust is different from the original component metals. 5. Burning wood is a chemical reaction that forms a new product. 6. Levels of organization and formation of humans: cell -> tissue -> organ -> organ systems -> organism 7. Cells are to tissues, as tissues are to organs, and as organs are to organ systems. 8. Tissues are composed of similar cells that perform similar functions. 9. Our bodies have various systems. Many of these systems work together to help us survive. Each system has its functions, but at the same time its functions are helped by the function of another body system. Our skeletal and muscular system helps us move our body (arms, legs, etc.). 10. Our skeletal system helps us protect and support our bodies. 11. Our adult life skeletal system is made up of about 205 bones. 12. Our endocrine system helps us control our body regulations and growth. Our endocrine system produces hormones. 13. Our digestive system is where digestion of nutrients occurs. As the food moves through the system, every organ has its function. Ex. Absorption of nutrients occurs in the small intestine. Nutrients are absorbed here and are enters our blood stream. Our blood stream then is responsible for carrying nutrients throughout the body. 14. The excretory system is responsible for the elimination of waste products from our systems. 15. Our nervous and muscular systems are responsible together in responding to stimuli (nervous input) that will make us blink, jump when startled, and responsible for our reflexes. 16. Stimulus is a change in the environment that causes a response from our nervous system. 17. Respiratory system: lungs absorb oxygen and this oxygen is delivered to the cells in our bodies. This oxygen is used for cellular respiration. 18. The digestive system: brakes down food and transports nutrients so they can be absorbed by the small intestine into the blood stream. 19. Circulatory system: main function is to transport nutrients and oxygen throughout our bodies. Circulatory system network for transportation of materials that are essential for our bodies. 20. Atoms are made up of protons, neutrons, and electrons. Protons are positive charged, electrons are negative charged, and neutrons are not either positive or negative charged particles. 21. DNA in a cell provides information of hereditary (genetic information). 22. Water (H2O) has 2 atoms of Hydrogen and 1 atom of Oxygen. 23. Water is another example of a substance. It is a COMPOUND made out of two elements. 24. NH3 = ammonia is composed of 1 atom of Nitrogen and 3 atoms of Hydrogen. 25. Why doesn’t oil mix with water? Water is a “polar” solvent. Polar solvent doesn’t dissolve in non polar solutes like oil. 26. Oil is a non polar solute. 27. A solute is what gets dissolved in a solvent. 28. Water is a solvent. Sometimes referred to as the universal solvent. 29. Look at figure 5 from page 215 from your textbook. Identify crest, wavelength, and trough. 30. Review figure 18 from page 318 from your textbook. Understand the pH scale. Remember a pH of 7 is neutral. Neutral means it’s not acidic or basic. Water is a neutral substance. 31. Ammonia and soap are useful products used at home. These are basic on the pH scale. 32. What are the 3 major parts of the ear? Figure 14 page 222. Outer ear, middle ear, and inner ear. These 3 parts work together. 33. Solubility: measurement that describes how much solute dissolves in a given amount of solvent. The ability of a given substance (solute) to dissolve in a solvent. 34. Intensity of sound waves is measured in decibels (dB). 35. Sound waves travel faster through solids. Sound waves travel only through matter. 36. Cell membrane controls what enters or exits the cell. 37. A nucleus membrane surrounds the nucleus. The nucleus is within the cell in its cytoplasm. The entire cell is protected and surrounded by the cellular membrane. A similar membrane called plasma membranes surrounds cells from plants. 38. Nucleus controls most activities of the cell. 39. Review figure 3 from page 364 (animal cell) 40. Review figure 4 from page 365 (plant cell) 41. Cell Theory: Composed of 3 main ideas: A) All living things are made of one or more cells, B) The cell is the basic unit of life, and C) all cells come from cells that already exist. 42. Transverse waves, compressional waves, and electromagnetic waves are 3 types of waves that transports energy. 43. Volume is a property of a liquid that can be measured using a measuring cup. 44. Theory: explanation or model that is backed by results obtained by many tests and experiments. 45. The Periodic Table is a model used by scientist to determine the properties of elements. 46. The atomic number of an element tells the number of protons in the nucleus of that given element. 47. A mixture is 2 or more substances combined that don’t make a new substance. 48. Conic projections: a type of map that is made by projecting points and lines from a globe onto a cone. 49. Contour lines connect same areas of similar elevations. 50. The streak test provides the color property of the minerals. The streak test requires a piece of ceramic to which the mineral is streaked. The revealing color on the streak will identify the minerals present. 51. Weathering is a mechanical or chemical surface process that breaks rocks into smaller pieces. 52. When water finds its way through cracks on rocks, when this water freezes it will produce fractures in the rock. When water freezes it expands, forcing the cracks to open further. In freezing waters, molecules move apart. 53. Chemical weathering is most rapid in tropical regions. 54. All minerals are inorganic solids. 55. Fossils give up evidence of ancient life. 56. Animals with hard parts produce better fossils. 57. Fossils are most likely be formed in sedimentary rocks. 58. Paleontologist study fossils. 59. Principal of succession: THE PRESENT IS THE KEY TO THE PAST. 60. Superposition is the principal that states that the oldest rocks are always at the deepest level. The rocks closer to the surface are newer. This is always true if the surface is undisturbed. 61. The oldest fossils are always found at the oldest rock level. The oldest rocks are found deeper into the surface. 62. The Pacific Ocean is found to the west of the United States. 63. Lithosphere: rigid layer of Earth made of the crust and a part of the upper mantle. 64. Earthquakes occur where one plate tectonic slides past another plate. 65. The Atlantic has the most spreading boundaries. 66. Seismic waves are produced by earthquakes. 67. Epicenters have to do with earthquakes, not volcanoes. 68. Pangaea is the theory of the existence of a super continent once existed. 69. Density is mass over volume of a substance. D = m/V 70. Bacteria is a unicellular organism; this means is a single (1) cell organism. 71. Amphibians send part of their life in water and some on land. 72. Earth science is the science that studies Earth and space.