Earth Science Module, Study notes of Earth science

Download Earth Science Module and more Study notes Earth science in PDF only on Docsity! Senior High School DepED DEPARTMENT Mf OF EDUCATION Earth Science Quarter 2 - Module 1: Weathering CO_Q2_Earth Science (SHS)_ Module 1 Earth Science Alternative Delivery Mode Quarter 2 — Module 1 — Weathering First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education Secretary: Leonor Magtolis Briones Undersecretary: Diosdado M. San Antonio Development Team of the Module Development Team of the Module Writers: Lorna B. Alvarez Editors: Randie B. Atienza and Eleneth D. Escalona Reviewers: Marionel U. Briz, Francia C.Silva, Rowena D. Cabanding and Job S. Zape Jr. Illustrator: Patrick Lemuel V. Reyes Layout Artist: Paulina S. Crescini, Leomar G. Paracha Management Team: Wilfredo E. Cabral Job S. Zape Jr. Eugenio S. Adrao Elaine T. Balaogan Felizardo O. Bolafios Joephi F. Falqueza Sacoro R. Comia Generiego O. Javier Rowena D. Cabanding Marieta N. Perez Printed in the Philippines by Department of Education — Region IV-A CALABARZON Office Address: Gate 2 Karangalan Village, Barangay San Isidro Cainta, Rizal 1800 Telefax: 02-8682-5773/8684-491 4/8647-7487 E-mail Address: region4a@deped.gov.ph What I Need to Know Most Essential Learning Competency: Describe how rocks undergo weathering This lesson discusses the key concepts about weathering and how it is related to soil production. It also tackles the agents of weathering that are responsible for the breaking of rocks. This learning material targets students to acquire competency. Specifically, it directs students to explain how weathering occurs through differentiating physical weathering from chemical weathering. Lessons are bounded on the performance and content standard, learning competencies and level of the learners. After going through this lesson, you are expected to: explain how rocks undergo weathering; identify the different agents of weathering; describe physical, chemical, and biological weathering; and identify the different types of physical, chemical, and biological weathering. AONE What I Know Directions: Read and analyze the following questions. Select the letter of the best answer. Write your answers in a separate sheet of paper. 1. Which of the following best describes weathering? a.The process by which rocks are exposed to severe weather b.The process by which rocks are formed by heat and pressure c.The mechanical or chemical process by which rocks are broken down d.The process by which rocks are chemically strengthened due to exposure to heat and pressure 2. How does gravity contribute to weathering? a. by abrasion of the rocks c. by dissolving rocks’ particles b. by expansion of rocks d. by creating holes in rocks CO_Q2 Earth Science (SHS)_ Module 1 3. Which of the following is NOT an example of physical weathering? a. Freeze- thaw b. Wind blowing sand onto a rock c. Plant that grows on the cracks of the rocks d. Abrasion due to the movement of glaciers 4. What happens to pieces of rock as they are transported by a river? a. they get smaller and rounder c. smaller and more jagged b. much larger and rounder d. gets larger and more jagged 5. In hydration, water is an active agent of chemical weathering. What happens when water loosely combines with the minerals of the rock? a. cements them together b. converts the mineral into another kind c. transports the rock into a lower altitude d. weakens the molecular binding of the minerals 6. What are the two things that affect the rate of weathering? a. time and date c. rain and ice b. type of rock and climate d. size of rock and time of the year 7. Which of the following best describes chemical weathering? a. The process by which rocks are broken down by physical forces b. The process by which rocks are broken down by chemical means c. The process by which rocks are broken down by anthropogenic activities d. all of the above 8. Weak organic acids are produced by the action of the growing roots of lichens. These acids react with some minerals in rocks resulting in the decomposition of rocks. How will you classify this process? a. Physical weathering b. Chemical weathering c. Biological weathering through physical means d. Biological weathering through chemical compounds 9. Which of the following conditions promotes slow chemical weathering? a. fracturing c. high amount of rainfall b. thick soil d. cold temperature CO_Q2 Earth Science (SHS)_ Module 1 10. Which type of rocks tends to weather more rapidly through hydrolysis process? a. Rocks that contain iron. c. Rocks that are impermeable. b. Rocks that contain quartz. d. Rocks that contain feldspar. 11. Which is an example of oxidation? a. Rust decomposes rocks completely with passage of time. b. Some of the minerals get dissolved in water. c. The joints enlarge in size and lime is removed in the solution. d. Due to the absorption of water by rocks, its volume increases. 12. Which of these statements is NOT true about mechanical weathering? a. breaks rock material into smaller pieces b. changes the chemical composition of rocks c. strong winds carrying sand blows on the rocks d. beach rock gets hot in daytime and cools in the evening thus creating fracture on the rock 13. Which of the following activities has resulted in an increased rate of chemical weathering through acidification? 1. The production of SO2 and NO in the atmosphere that combine with rain to form acids. 2. The release of too much carbon dioxide in the air that turn rain into weak acid. 3. The disintegration of rocks during construction and mining 4. The growth of the plant roots on the rock crack. a. 1 only b. 2 only c, 1 and2 d. 2 and 3 14. Which is not included in the group? a. carbonation _b. abrasion c. acidification d. hydration 15. In which of the following climates will chemical weathering be most rapid? a. coldanddry b.coldand humid c.hotanddry d. hot and humid Weathering The Earth is constantly changing or altered physically as we have observed. The changes driven by different forces of nature create new land forms. One of these forces is weathering. This process includes degradation or breaking down of rocks into smaller segments known as sediments. It occurs when mechanical force is applied on rocks or through chemical reactions happening on the surface or within the rocks. In this lesson, you are going to describe how rocks undergo weathering and the different agents that cause weathering on rocks. CO_Q2 Earth Science (SHS)_ Module 1 2. Freeze-thaw. It occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart. It occurs in mountainous regions like the Alps or Snowdonia. It occurs through the following process: Rainwater or snow- melt collects in cracks in the rocks— at night the temperature drops and the water freezes and expands-— the increases in volume of the ice exerts pressure on the cracks in the rock, causing them to split further open— during the day the ice melts and the water seeps deeper into the cracks — at night, the water freezes again. 3. Exfoliation. It can happen as cracks develop parallel to the land surface as a consequence of the reduction in pressure during uplift and erosion. It occurs typically in upland areas where there are exposures of uniform coarsely crystalline igneous rocks. The following are the process of exfoliation. The rock mass at depth is under high pressure from underlying rocks. It tends to be uniform and lack fractures. — As progressive erosion occurs, the rock mass is subjected to progressively lower pressure of overlying rocks which leads to tension in directions at right angles to the land surface — this tension is relieved by formation of cracks which follow the land surface. They are relatively flat on plateaus but can be steep on the flanks of mountains which are called exfoliation domes — once the crack is developed; water enters and causes chemical weathering leading to the formation of new low- density minerals. This enhances the cracks and encourages slabs of rock to detach from the surface. B. Chemical weathering fi 5 Chemical weathering is caused by rainwater reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic. These chemical processes need water, and occur more rapidly at higher temperature, so warm, damp climates are best. Chemical weathering (especially hydrolysis and oxidation) is the first stage in the production of soils. Kapurpurawan Rock formation at Burgos Ilocos Norte There are different types of chemical weathering, the most important are: 1. Carbonation - Carbon dioxide in the air dissolves in rainwater and becomes weakly acidic. This weak “carbonic acid” can dissolve limestone as it seeps into cracks and cavities. Over many years, solution of the rock can form spectacular cave systems. CO_Q2 Earth Science (SHS)_ Module 1 2. Acidification - Polluting gases, like sulfur dioxide and nitrogen oxide dissolve in rainwater to make stronger acids. When this rainwater falls, we get acid rain. This acid attacks many rock types, both by solution and hydrolysis, seriously damaging buildings and monuments. 3. Hydrolysis - the breakdown of rock by acidic water to produce clay and soluble salts. Hydrolysis takes place when acid rain reacts with rock-forming minerals such as feldspar to produce clay and salts that are removed in solution. The only common rock-forming mineral that is not affected is quartz, which is a chemically resistant mineral. Therefore, quartz and clay are the two of the most common minerals in sedimentary rocks. 4. Hydration —- A type of chemical weathering where water reacts chemically with the rocks, modifying its chemical structure. Example: H2O (water) is added to CaSO, (calcium sulfate) to create CaSO, + 2H2O (calcium sulfate dihydrate). It changes from anhydrite to gypsum. 5. Oxidation - the breakdown of rock by oxygen and water, often giving iron- rich rocks a rusty-colored weathered surface. C. Biological weathering Biological weathering of rocks occurs when rocks are weakened by different biological agents like plants and animals. When plant roots grow through rocks, it creates fracture and cracks that result eventually to rock breakage. It can be classified into: Belete tree (Ficus sp.) grows in a commercial building in Lemery Batangas. 1. Biological Weathering by Physical Means. Burrowing animals like shrews, moles and earthworms create holes on the ground by excavation and move the rock fragments to the surface. These fragments become more exposed to other environmental factors that can further enhance their weathering. Furthermore, humans also indirectly contribute to biological weathering by different activities that cause rocks to break. 2. Biological Weathering by Chemical Compounds. Some plants and animals also produced acidic substances that react with the rock and cause its slow disintegration. 7 ©O_Q2 Earth Science (SHS)_ Module 1 What’s More A. Directions: Write C if the statement is correct and | if the statement is incorrect. Write your answers in a separate sheet of paper. 1. Gravity is one of the agents of weathering. 2. Exfoliation occurs when water continually seeps into cracks, freezes and expands eventually breaking the rock apart. 3. Carbonation occurs when carbon dioxide dissolved in water makes acid and reacts with rocks. 4. Burrowing animals cannot contribute on weathering of rocks. 5. Hydrolysis takes place when acid rain reacts with rock-forming minerals such as feldspar to produce clay and salts that are removed in solution. 6. Animals produce acidic compounds that can cause rock disintegration. 7. Sulfur dioxide and nitrogen oxide when mix with water produces basic substance that can break down rocks’ components. 8. Humans indirectly contribute on weathering. 9, Water alters chemical components of rocks that cause weathering. 10. Earthworms are physical weathering agent. B. Directions: Write P if the given is a physical weathering, C if chemical weathering and B if it is biological weathering. Write your answers in a separate sheet of paper. . Balete tree grows at the wall of the building. . Construction workers use power tools to break the rocks. . Insects secrete acidic substance on rocks. . Glaciers carve its pathways. . Rainwater combined with iron on rocks produces rusts. Aaa fw NH . Carbon dioxide mix with water produces carbonic acid that reacts with rocks, 7. Water freezes in a large crack of a rock. 8. Strong winds blow small particles of the rocks. 9. Rocks form bubbles after the heavy pour of acid rain. 10. Rocks fall down from the mountain and break. CO_Q2 Earth Science (SHS)_ Module 1 7. Which of the following is an example of biological weathering? a. Freeze- thaw b. Wind blowing sand onto a rock c. Abrasion due to the movement of glaciers d. Plant that grows on the cracks of the rocks 8. What happens to pieces of rock as they are transported by a river? a. smaller and more jagged c. much larger and rounder b. gets larger and more jagged d. they get smaller and rounder 9. In hydration, water is an active agent of chemical weathering. What happens when water loosely combines with the minerals of the rock? a. cements minerals of the rock together b. converts the mineral into another kind c. transports the rock into a lower altitude d. breaks down the molecular binding of the minerals 10. Which type of rocks tends to weather more rapidly through the hydrolysis process? a. Rocks that contain iron. c. Rocks that contain feldspar. b. Rocks that contain quartz. d. Rocks that are impermeable. 11. Which is an example of oxidation? a. Some of the minerals get dissolved in water. b. Rust decomposes rocks completely with passage of time. c. The joints enlarge in size and lime is removed in the solution. d. Due to the absorption of water by rocks, its volume increases. 12. What are the two things that affect the rate of weathering? a. rain and ice c. type of rock and climate b. time and date d. size of rock and time of the year 13. Which of the following best describes chemical weathering? a. The process by which rocks are broken down by physical forces b. The process by which rocks are broken down by chemical means c. The process by which rocks are broken down by anthropogenic activities d. all of these 14. Weak organic acids are produced by the action of the growing root of lichens. These acids react with some minerals in rocks resulting in the decomposition of rocks. How will you classify this process? a. Physical weathering b. Chemical weathering c. Biological weathering through physical means d. Biological weathering through chemical compounds Il €O_Q2 Earth Science (SHS)_ Module 1 15. Which of the following conditions promotes slow chemical weathering? a. fracturing c. high rainfall b. thick soil d. cold temperatures % \ additional Activities RS Directions: Create a photo gallery of places showing the examples of weathering in your locality. Upload this on social media and put a #weathering # the type of weathering. Write a short discussion on the pictures. Tag it with your teachers and classmates 12 CO _Q2 Earth Science (SHS)_ Module 1 Answer Key da Vv s.eUM BovVvoo wwe oa7~oananak da Vv s.eUM BO PNDMVAYH HE OwN ATA B BovvaoVwwHraAa~aa7~a7oR Pepe ge ONE ouwon BO PNAARENE OuvumEOPISA yuourssessy PEnNanayne mouy 1 7eUM rs > d'or Ooumworaroa CO_Q2 Earth Science (SHS)_ Module 1 13