2nd Quarter Reviewer in Earth Science 7 SY 2024-2025 PDF

St. Agnes Academy, Inc. Legazpi City Junior High School SY 2024-2025 SECOND QUARTERLY REVIEWER IN EARTH SCIENCE AND SCIE...

St. Agnes Academy, Inc. Legazpi City Junior High School SY 2024-2025 SECOND QUARTERLY REVIEWER IN EARTH SCIENCE AND SCIENTIFIC RESEARCH 7 KEY POINTS Radiation What it is: Radiation is the transfer of energy through electromagnetic waves. It does not require a medium to travel, which is why sunlight (solar radiation) can move through the vacuum of space to Earth. How it interacts with the atmosphere: o About 30% of incoming solar radiation is reflected into space by clouds, atmospheric particles, and Earth’s surface (albedo effect). o The remaining 70% is absorbed by the atmosphere, land, and oceans, warming the planet. o Greenhouse gases (e.g., CO₂, water vapor, methane) trap some of this heat, keeping Earth warm enough to support life. Example: Sunlight heating the ground or water directly. Conduction What it is: Conduction is the transfer of heat through direct contact between substances. How it interacts with the atmosphere: o When the Sun’s radiation heats the Earth’s surface, that heat is transferred to the air molecules directly touching the ground through conduction. o This process mainly occurs near the surface, as air is a poor conductor of heat. Example: The ground heating the air immediately above it on a sunny day. Convection What it is: Convection is the transfer of heat through the movement of fluids (liquids or gases), caused by differences in temperature and density. How it interacts with the atmosphere: o Warm air near the surface becomes less dense and rises, while cooler, denser air sinks, creating convection currents. o This movement distributes heat through the atmosphere and drives weather patterns like winds and storms. Example: The formation of clouds and thunderstorms as warm air rises, cools, and condenses. Key Interactions of the Three Processes: Radiation provides the initial energy by heating the Earth’s surface. Conduction transfers that heat to the air in direct contact with the surface. Convection then distributes heat throughout the atmosphere, influencing weather and climate. KEY POINTS Troposphere Absorption: Absorbs some infrared radiation from Earth's surface, contributing to the greenhouse effect. Reflection: Clouds and aerosols reflect incoming solar radiation back into space. Scattering: Responsible for scattering sunlight, creating the blue color of the sky (Rayleigh scattering). Stratosphere Absorption: The ozone layer absorbs most of the Sun's harmful ultraviolet (UV) radiation. Reflection: Generally reflects minimal solar energy but helps regulate energy flow. Scattering: Limited scattering occurs but not as significant as in the troposphere. Thermosphere Absorption: Absorbs high-energy X-rays and ultraviolet radiation, causing high temperatures. Reflection: Little to no reflection of solar energy. Scattering: Scattering is minimal, but this layer influences auroras (interaction of solar winds with Earth's magnetic field). Exosphere Absorption: Very thin; negligible absorption of solar energy. Reflection: Does not reflect solar energy due to lack of particles. Scattering: Minimal scattering; almost a transition to outer space. PRACTICE QUESTIONS: 1. How does solar energy initially interact with the atmosphere upon reaching Earth? A. It is fully absorbed by the troposphere B. It is completely reflected into space C. It is partially absorbed, reflected, and scattered by the atmosphere D. It bypasses the atmosphere entirely 2. Which atmospheric layer is primarily responsible for absorbing harmful ultraviolet (UV) radiation? A. Troposphere B. Stratosphere C. Thermosphere D. Exosphere 3. What phenomenon in the troposphere causes the blue color of the sky? A. Absorption of infrared radiation B. Scattering of sunlight (Rayleigh scattering) C. Reflection by clouds D. Convection currents 4. Which layer absorbs high-energy X-rays and ultraviolet radiation, leading to extreme temperatures? A. Troposphere B. Stratosphere C. Thermosphere D. Exosphere 5. What is the primary role of clouds and aerosols in the atmosphere regarding solar energy? A. Absorbing solar energy B. Reflecting solar energy back into space C. Generating greenhouse gases D. Enhancing convection currents 6. In which atmospheric layer is most of the infrared radiation from Earth's surface absorbed, contributing to the greenhouse effect? A. Troposphere B. Stratosphere C. Thermosphere D. Exosphere 7. How does the exosphere interact with solar energy? A. It reflects most solar radiation B. It absorbs high-energy radiation C. It has negligible interaction due to its low particle density D. It scatters sunlight, causing auroras 8. In a real-world scenario, how do atmospheric layers protect life on Earth from harmful solar energy? A. The troposphere blocks all UV and X-rays B. The ozone layer in the stratosphere absorbs most UV radiation C. The thermosphere reflects UV and X-rays into space D. The exosphere creates a dense barrier against solar energy 9. How is solar energy transferred through the atmosphere to the Earth’s surface? A. Through reflection by the thermosphere B. Through scattering in the exosphere C. As radiation passing through all layers D. As conduction from one layer to the next 10. What real-world process demonstrates the interaction of solar energy with atmospheric layers and life on Earth? A. Photosynthesis, which depends on sunlight reaching the surface B. The reflection of sunlight by the thermosphere C. The scattering of all solar energy in the exosphere D. The absorption of visible light only in the stratosphere KEY POINTS Earth’s Tilt on its Axis: The Earth's axis is tilted at an angle of approximately 23.5 degrees relative to its orbital plane around the Sun. PRACTICEThisQUESTIONS: tilt is constant as the Earth orbits the Sun, meaning the angle at which sunlight hits different parts of the Earth changes throughout the year. Impact on Day Length: Due to the tilt, different hemispheres of the Earth receive varying amounts of sunlight during different times of the year. In summer, the hemisphere tilted towards the Sun experiences longer daylight hours because it is facing the Sun more directly. In winter, the hemisphere tilted away from the Sun experiences shorter daylight hours because it is facing the Sun at a slanted angle, spreading the sunlight over a larger area. Variation in Sunlight Intensity: The tilt also affects the intensity of sunlight. When a hemisphere is tilted towards the Sun, the Sun’s rays hit that area more directly (at a steeper angle), making the sunlight more concentrated and intense. Conversely, when the hemisphere is tilted away, the sunlight hits at a shallower angle, spreading over a larger area and making it less intense. The Changing Seasons: The tilt of the Earth causes the seasons: o Summer in one hemisphere occurs when it is tilted towards the Sun, resulting in longer days and more direct sunlight. o Winter occurs when that hemisphere is tilted away, resulting in shorter days and weaker sunlight. Spring and autumn are transitional periods when both hemispheres experience nearly equal amounts of daylight. Equinoxes and Solstices: The equinoxes (around March 21 and September 21) occur when the tilt of the Earth is such that the Sun is directly over the equator, leading to approximately equal day and night lengths. The solstices (around June 21 and December 21) occur when the tilt of the Earth is at its extreme, resulting in the longest or shortest day of the year depending on the hemisphere. Geographical Differences: Near the equator, the length of day remains relatively constant throughout the year. Closer to the poles, the variation in day length becomes more extreme, with some regions experiencing periods of constant daylight or darkness (polar day and polar night). PRACTICE QUESTIONS: 1. What is the primary factor that causes the intensity of sunlight to vary across Earth’s surface throughout the year? A. The Earth's rotation on its axis B. The tilt of the Earth relative to its orbit C. The speed of the Earth’s revolution D. The distance between the Earth and the Sun 2. What is the tilt of the Earth’s axis relative to its orbital plane around the Sun? A. 15.5° B. 23.5° C. 30° D. 45° 3. How does the tilt of the Earth affect sunlight intensity during the summer solstice in the Northern Hemisphere? A. The Sun's rays are most direct at the equator B. The Northern Hemisphere receives the most direct sunlight C. The Southern Hemisphere receives the most direct sunlight D. The Sun’s rays are scattered evenly across both hemispheres 4. What happens to the length of daytime during the winter solstice in the Southern Hemisphere? A. Daytime is the longest of the year B. Daytime is the shortest of the year C. Daytime is equal to nighttime D. Daytime is unaffected 5. What term describes the two times a year when day and night are approximately equal in length everywhere on Earth? A. Solstice B. Equinox C. Perihelion D. Aphelion 6. During the vernal equinox, where are the Sun's rays most directly focused? A. At the Tropic of Cancer B. At the Tropic of Capricorn C. At the Equator D. At the poles 7. How does the Earth's tilt affect the Arctic Circle during the summer solstice? A. It experiences 24 hours of daylight B. It experiences 24 hours of darkness C. It experiences equal day and night D. It receives no sunlight at all 8. What causes the length of daytime to change throughout the year in different locations? A. Variations in the Earth's rotation speed B. The Earth’s tilted axis and its orbit around the Sun C. Changes in the Sun’s intensity D. Shifts in the Earth’s magnetic field 9. When it is summer in the Northern Hemisphere, what season is it in the Southern Hemisphere? A. Winter B. Spring C. Summer D. Fall 10. How does the tilt of the Earth impact the seasons? A. It causes equal heating of both hemispheres year-round B. It determines which hemisphere receives more direct sunlight during different times of the year C. It makes the Sun rise and set at the same time year-round D. It only affects regions near the equator. Answer Key to Practice Questions: 1. How does solar energy initially interact with the atmosphere upon reaching Earth? Answer: C. It is partially absorbed, reflected, and scattered by the atmosphere 2. Which atmospheric layer is primarily responsible for absorbing harmful ultraviolet (UV) radiation? Answer: B. Stratosphere 3. What phenomenon in the troposphere causes the blue color of the sky? Answer: B. Scattering of sunlight (Rayleigh scattering) 4. Which layer absorbs high-energy X-rays and ultraviolet radiation, leading to extreme temperatures? Answer: C. Thermosphere 5. What is the primary role of clouds and aerosols in the atmosphere regarding solar energy? Answer: B. Reflecting solar energy back into space 6. In which atmospheric layer is most of the infrared radiation from Earth's surface absorbed, contributing to the greenhouse effect? Answer: A. Troposphere 7. How does the exosphere interact with solar energy? Answer: C. It has negligible interaction due to its low particle density 8. In a real-world scenario, how do atmospheric layers protect life on Earth from harmful solar energy? Answer: B. The ozone layer in the stratosphere absorbs most UV radiation 9. How is solar energy transferred through the atmosphere to the Earth’s surface? Answer: C. As radiation passing through all layers 10. What real-world process demonstrates the interaction of solar energy with atmospheric layers and life on Earth? Answer: A. Photosynthesis, which depends on sunlight reaching the surface ANSWER KEY TO PRACTICE QUESTIONS: 1. What is the primary factor that causes the intensity of sunlight to vary across Earth’s surface throughout the year? Answer: B. The tilt of the Earth relative to its orbit 2. What is the tilt of the Earth’s axis relative to its orbital plane around the Sun? Answer: B. 23.5° 3. How does the tilt of the Earth affect sunlight intensity during the summer solstice in the Northern Hemisphere? Answer: B. The Northern Hemisphere receives the most direct sunlight 4. What happens to the length of daytime during the winter solstice in the Southern Hemisphere? Answer: A. Daytime is the longest of the year 5. What term describes the two times a year when day and night are approximately equal in length everywhere on Earth? Answer: B. Equinox 6. During the vernal equinox, where are the Sun's rays most directly focused? Answer: C. At the Equator 7. How does the Earth's tilt affect the Arctic Circle during the summer solstice? Answer: A. It experiences 24 hours of daylight 8. What causes the length of daytime to change throughout the year in different locations? Answer: B. The Earth’s tilted axis and its orbit around the Sun 9. When it is summer in the Northern Hemisphere, what season is it in the Southern Hemisphere? Answer: A. Winter 10. How does the tilt of the Earth impact the seasons? Answer: B. It determines which hemisphere receives more direct sunlight during different times of the year