Composition 6th Grade Science Sample Assessment Items Ocean water differs from freshwater in that it has. A. a lower temperature B. a higher temperature C. a higher concentration of silicon dioxide D. a higher concentration of sodium chloride* Which are the two most abundant elements dissolved in seawater? A. Ca and Cl B. Na and Mg C. Na and Cl* D. Mg and Ca One way the North Atlantic Ocean is different from the South Pacific Ocean is that the North Atlantic has. A. a greater average depth B. a higher average pressure C. a lower average temperature D. a larger average concentration of salt* The salts in the sea come from. A. acid rain B. particles falling from space C. organisms that live in the sea D. weathering and erosion of rocks* Many gallons of freshwater pour into the oceans each day. However, the salinity balance is maintained because. A. sea organisms consume the freshwater. B. the water becomes salty as it enters the ocean. C. water continuously evaporates back out of the ocean.* D. salty glacial water is also evaporating from the ice caps.
There are many bodies of water in or next to Georgia, including Lake Blackshear and the Atlantic Ocean. What is MOST LIKELY a difference between the water in Lake Blackshear and the water in the Atlantic Ocean? A. The water in Lake Blackshear is always much colder than the water in the Atlantic Ocean. B. The water in the Atlantic Ocean contains more dissolved minerals than the water in Lake Blackshear.* C. The water in Lake Blackshear comes from rivers, while the water in the Atlantic Ocean comes from rain. D. The water in the Atlantic Ocean is part of the water cycle, but the water in the Lake Blackshear is not. When ice forms in the oceans, what happens to the water found directly underneath the newly formed ice? A. it becomes colder B. it becomes warmer C. it becomes denser D. it becomes more salty* Tropical seas have a high rate of evaporation. Because of this, the water in tropical seas will have higher. A. wave crests B. amounts of algae C. daily temperatures D. salt concentrations* Oceans contain many dissolved elements like calcium, sodium, and chlorine and these elements plus others combine to form the salts in the oceans. Which of the following sources is a major source of calcium and sodium in oceans? A. gases from active volcanoes B. weathering and erosion of rocks* C. pollutants from industrial wastes D. acid rain caused by air pollution Which of these increases as a submarine dives deeper into the ocean? A. The water pressure* B. The water temperature C. The freshness of the water D. The number of plants in the water
Label the four major oceans in the diagram below. Describe how the flow of weathered and dissolved rock material towards the ocean affect the chemical composition (makeup) of the ocean? Explain why deep water near the equator has a higher salinity than other parts of the ocean. Why is water colder the deeper you go in the ocean? Which location in the diagram to the right is most likely to have the greatest pressure, the coldest temperatures, and the greatest density? Explain.
Subsurface Topography The floor of the ocean. A. is smooth and sandy B. has rivers and lakes C. is hidden and unknown D. has mountains and trenches* The section of a continent that lies just off the shoreline and extends beneath the ocean is called the continental. A. plain B. shelf* C. basin D. ridge Which best represents the order of seafloor features as you move from the shoreline to the deep ocean? A. continental slope continental shelf continental rise mid-ocean ridge B. continental rise continental shelf mid-ocean ridge continental slope C. continental shelf continental slope continental rise mid-ocean ridge* D. mid-ocean ridge continental rise continental shelf continental slope If you could look at the deep ocean floor, which is the best description of what you would see? A. flat, silt-covered, lifeless regions B. high mountains and deep valleys* C. ocean ridges with active volcanoes D. coral reefs with many varieties of life Ridges, tectonic plate boundaries, and hydrothermal vents are physical features found on our planet. Where are these features found MOST OFTEN? A. in the middle of huge lakes B. around the edges of deserts C. at the bottom of Earth's oceans* D. on top of mountains on continents
What are mid-ocean ridges? A. They are areas where tectonic plates meet. B. They are narrow valleys that run along the bottom of the oceans. C. They are areas underwater where thick layers of sediment have accumulated. D. They are areas of underwater mountain chains located near many active volcanoes.* Algae and other producers need lots of sunlight. Most ocean algae would be found in the water. A. on the abyssal plain B. in the oceanic trench C. above the continental shelf* D. beside the continental slope At which ocean feature would the greatest amount of water pressure be exerted? A. Trench* B. Abyssal plain C. Continental shelf D. Continental slope
Ridges, tectonic plate boundaries, and hydrothermal vents are physical features found on our planet. Where are these features found MOST OFTEN? A. in the middle of huge lakes B. around the edges of deserts C. at the bottom of Earth's oceans D. on top of mountains on continents Identify the physical features of the ocean floor numbered in the diagram above.