https://www.khanacademy.org/science/strengthened-shs-earth-and-space-science-1/x006d5d274c051fd7:earth-s-materials-and-resources/x006d5d274c051fd7:rocks-and-soils/v/rock-cycle 2020-08-15T00:56:31Z Rock cycle We bet you thought that rocks are just rocks, but the truth is there are three different kinds of rocks. Learn the differences between sedimentary, metamorphic and igneous rocks. MIT+K12 video https://cdn.kastatic.org/googleusercontent/8bwj0nki0o0UPqlwO0rx-GO6n0yFhuBsnKMFaiAjj9ncUhcm2XFbl9189rNgpe5823g3-zR-NNwRMhx1EcRfpL4 Rock cycle We bet you thought that rocks are just rocks, but the truth is there are three different kinds of rocks. Learn the differences between sedimentary, metamorphic and igneous rocks. https://cdn.kastatic.org/ka-youtube-converted/pm6cCg_Do6k.mp4/pm6cCg_Do6k.mp4 272 Rocks and soils https://www.khanacademy.org/science/middle-school-earth-and-space-science/x87d03b443efbea0a:the-geosphere/x87d03b443efbea0a:the-rock-cycle/a/the-rock-cycle 2022-08-16T21:35:34.489399084Z The rock cycle Review your understanding of the rock cycle in this free article aligned to NGSS standards. article https://www.khanacademy.org/science/strengthened-shs-earth-and-space-science-1/x006d5d274c051fd7:earth-s-materials-and-resources/x006d5d274c051fd7:rocks-and-soils/v/soil 2025-07-29T05:26:51.951860141Z Soil Did you know it takes thousands of years to make just a spoonful of soil? In this fun and visual video, we explore: 1. What soil is made of 2. How it forms from rocks 3. Types of soil and what grows in them 4. The role of earthworms and decomposers 5. Why soil is so important—and how to protect it! Bitasta Datta video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Soil Did you know it takes thousands of years to make just a spoonful of soil? In this fun and visual video, we explore: 1. What soil is made of 2. How it forms from rocks 3. Types of soil and what grows in them 4. The role of earthworms and decomposers 5. Why soil is so important—and how to protect it! https://cdn.kastatic.org/ka-youtube-converted/JdDOv0HXDpw.mp4/JdDOv0HXDpw.mp4 330 Rocks and soils https://www.khanacademy.org/science/strengthened-shs-earth-and-space-science-1/x006d5d274c051fd7:earth-s-materials-and-resources/x006d5d274c051fd7:rocks-and-soils/a/soil-and-crops 2025-08-05T10:32:41.418758425Z Soil and Crops explore how different types of soil—clayey, sandy, and loamy—support different crops like rice, cotton, and pulses. Learn why farmers match crops with soil type, how water-holding capacity plays a role, and discover real-life examples from India. A must-read for understanding the science behind successful farming! article https://www.khanacademy.org/science/strengthened-shs-earth-and-space-science-1/x006d5d274c051fd7:earth-s-materials-and-resources/x006d5d274c051fd7:rocks-and-soils/e/types-of-soil 2026-04-07T23:36:17.218592739Z Types of Soil Class 7 Science exercise on Types of Soil, based on NCERT Chapter 9. Includes concept-based MCQs, grouped True/False, fill in the blanks, and visual questions to boost understanding of soil types, properties, and crop suitability. Yajurva Joshi exercise https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:earth-systems-and-resources/x0b0e430a38ebd23f:earths-soil/a/soil-horizons-and-erosion 2022-09-16T02:37:58.737082894Z Soil horizons and erosion Review your understanding of soil formation, soil horizons, and erosion in this free article aligned to AP standards. article https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:earth-systems-and-resources/x0b0e430a38ebd23f:earths-soil/e/earths-soil 2026-03-25T13:00:37.369559121Z Earth's soil Apply your understanding of Earth's soil in this set of free practice questions aligned to AP standards. exercise https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:biodiversity-and-human-impacts/x230b3ff252126bb6:humans-and-biodiversity/v/human-impacts-on-ecosystems-video 2022-09-24T04:45:13.131282509Z Human impacts on ecosystems Anthropogenic changes (induced by human activity) in the environment—including habitat destruction, pollution, introduction of invasive species, overexploitation, and climate change—can disrupt an ecosystem and threaten the survival of some species. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/b1089156-0a34-4c68-b45e-9796f88b7fe9_1280_720_base.png Human impacts on ecosystems Anthropogenic changes (induced by human activity) in the environment—including habitat destruction, pollution, introduction of invasive species, overexploitation, and climate change—can disrupt an ecosystem and threaten the survival of some species. https://cdn.kastatic.org/ka-youtube-converted/K10qnzCYH54.mp4/K10qnzCYH54.mp4 336 Rocks and soils https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:aquatic-and-terrestrial-pollution/x0b0e430a38ebd23f:waste-disposal-reduction-and-treatment/v/solid-waste-disposal 2024-06-21T23:15:14.703721694Z Solid waste disposal Solid waste is most often disposed of in open dumps and sanitary landfills. A sanitary municipal landfill consists of a bottom liner (plastic or clay), a storm water collection system, a leachate collection system, a cap, and a methane collection system. However, landfills can contaminate groundwater, cause leachate pollution, and release harmful gases. Solid waste can also be disposed of through incineration, where waste is burned at high temperatures. Khan Academy video https://cdn.kastatic.org/ka_thumbnails_cache/0b70a8f3-f4f6-4b41-9992-519db064a1c2_1280_720_base.png Solid waste disposal Solid waste is most often disposed of in open dumps and sanitary landfills. A sanitary municipal landfill consists of a bottom liner (plastic or clay), a storm water collection system, a leachate collection system, a cap, and a methane collection system. However, landfills can contaminate groundwater, cause leachate pollution, and release harmful gases. Solid waste can also be disposed of through incineration, where waste is burned at high temperatures. https://cdn.kastatic.org/ka-youtube-converted/LOzMugtKmN4.mp4/LOzMugtKmN4.mp4 476 Rocks and soils https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:land-and-water-use/x0b0e430a38ebd23f:types-of-sustainable-practices/v/integrated-pest-management 2022-09-07T01:03:50.067296221Z Integrated pest management Integrated pest management (IPM) is a combination of methods used to effectively control pest species while minimizing the disruption to the environment. These methods include biological, physical, and limited chemical methods such as biocontrol, intercropping, crop rotation, and natural predators of the pests. Integrated pest management (IPM) minimizes disruptions to the environment and threats to human health but can be complex and expensive. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/03b8bb47-988e-4c38-84f0-27b2fb4590d0_1280_720_base.png Integrated pest management Integrated pest management (IPM) is a combination of methods used to effectively control pest species while minimizing the disruption to the environment. These methods include biological, physical, and limited chemical methods such as biocontrol, intercropping, crop rotation, and natural predators of the pests. Integrated pest management (IPM) minimizes disruptions to the environment and threats to human health but can be complex and expensive. https://cdn.kastatic.org/ka-youtube-converted/z2AMnP4nn2E.mp4/z2AMnP4nn2E.mp4 403 Rocks and soils https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:biodiversity-and-human-impacts/x230b3ff252126bb6:sustainability/a/human-activities-and-sustainability 2024-06-12T19:16:42.550703216Z Human activities and sustainability Learn how sustainability reduces the impact of human activities and conserves natural resources for future generations to use. article https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:land-and-water-use/x0b0e430a38ebd23f:types-of-sustainable-practices/a/sustainable-agriculture 2022-09-22T04:19:49.719617382Z Sustainable agriculture Review your understanding of sustainable agriculture, soil conservation, and soil fertility in this free article aligned to AP standards. article https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:land-and-water-use/x0b0e430a38ebd23f:types-of-sustainable-practices/e/types-of-sustainable-practices 2026-03-06T01:00:48.475972279Z Types of sustainable practices Apply your understanding of types of sustainable practices in this set of free practice questions aligned to AP standards. exercise