Geologists classify rocks in three groups, according to the major Earth processes that formed them. The three rock groups are igneous, sedimentary, and metamorphic rocks. Anyone who wishes to collect rocks should become familiar with the characteristics of these three rock groupsOne way to tell if a rock sample is sedimentary is to see if it is made from grains. Some samples of sedimentary rocks include limestone, sandstone, coal and shale. Igneous rocks form when magma from inside the Earth moves toward the surface, or is forced above the Earth's surface as lava and ash by a volcano. Igneous rocks are formed from melted rock that has cooled and solidifiedhe three rock groups are igneous, sedimentary, and metamorphic rocks
The United States government is comprised of three branches; the legislative branch, executive branch, and the judicial branch. Each branch works together to set the laws of the U.S. The congress, senate, and House of Representatives are under the legislative branch, which makes the laws.
