
rock - Kids | Britannica Kids | Homework Help
Rock, or stone, is a hard material made up of one or more minerals. Rock makes up the outer layer of Earth, called the crust. The lower parts of this layer are solid rock, or…
Obsidian | Rock, Color, Composition, & Uses | Britannica
May 4, 2025 · Obsidian generally contains less than 1 percent water by weight. Under high pressure at depth, rhyolitic lavas may contain up to 10 percent water, which helps to keep …
Chris Rock | Biography, Movies, TV Shows, & Facts | Britannica
Chris Rock (b. 1966) is an American comedian whose popular stand-up routine, which often addressed racial matters, led to a successful film career. His movies included I’m Gonna Git …
Standing Rock protests | Summary, Violence, & Outcome | Britannica
The Standing Rock protests were a campaign undertaken in North Dakota in 2016 and 2017 to halt the construction of the Dakota Access pipeline. Early resistance to the pipeline was …
rock - Students | Britannica Kids | Homework Help
Courtesy of Ernst ten Haaf. Sedimentary rock forms from rock fragments, sand, mud, and other materials that are compacted and cemented together at Earth’s surface. The materials that …
Rock - Social Change, Cultural Evolution, Music Revolution
Apr 17, 2025 · Rock - Social Change, Cultural Evolution, Music Revolution: How, then, should rock’s contribution to music history be judged? One way to answer this is to trace rock’s …
Rock - Structure, Texture, Composition | Britannica
May 12, 2025 · Rock - Structure, Texture, Composition: Physical properties of rocks are of interest and utility in many fields of work, including geology, petrophysics, geophysics, materials …
Metamorphic rock | Definition, Formation, & Facts | Britannica
May 7, 2025 · Metamorphic rock, any rock that results from the alteration of preexisting rocks in response to changing conditions, such as variations in temperature, pressure, and mechanical …
List of Musical Bands | Rock, Pop, Grunge | Britannica
This is an alphabetically ordered list of bands. See also band, rock, alternative rock, popular music, heavy metal, grunge, psychedelic rock, punk, and country
Rock and roll | History, Songs, Artists, & Facts | Britannica
Apr 23, 2025 · Rock and roll, style of popular music that originated in the United States in the mid-1950s and that evolved by the mid-1960s into the more encompassing international style …