- The Mount Rushmore National Memorial is a national memorial centered on a colossal sculpture carved into the granite face of Mount Rushmore (Lakota: Tȟuŋkášila Šákpe, or Six Grandfathers) in the Black Hills near Keystone, South Dakota, United States. Sculptor Gutzon Borglum designed the sculpture, called Shrine of Democracy, and oversaw the project’s execution from 1927 to 1941 with the help of his son, Lincoln Borglum. The sculpture features the 60-foot-tall (18 m) heads of four United States presidents: George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln, chosen to represent the nation’s birth, growth, development, and preservation, respectively. Mount Rushmore attracts more than two million visitors annually to the memorial park which covers 1,278 acres (2.00 sq mi; 5.17 km2). The mountain’s elevation is 5,725 feet (1,745 m) above sea level.
- South Dakota (Wikipedia)
South Dakota (/- dəˈkoʊtə/; Sioux: Dakȟóta itókaga, pronounced [daˈkˣota iˈtokaga]) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota Sioux Native American tribe, which comprises a large portion of the population with nine reservations currently in the state and have historically dominated the territory. South Dakota is the seventeenth largest by area, but the 5th least populous, and the 5th least densely populated of the 50 United States. As the southern part of the former Dakota Territory, South Dakota became a state on November 2, 1889, simultaneously with North Dakota. They are the 39th and 40th states admitted to the union; President Benjamin Harrison shuffled the statehood papers before signing them so that no one could tell which became a state first. Pierre is the state capital, and Sioux Falls, with a population of about 192,200, is South Dakota’s largest city.
- Aluminium (Wikipedia)
Aluminium (Aluminum in North American English) is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, nonmagnetic, and ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the twelfth-most common element in the universe. The radioactivity of 26Al, a more unstable isotope, leads to it being used in radiometric dating.