shell crust
71North America — North American. the northern continent of the Western Hemisphere, extending from Central America to the Arctic Ocean. Highest point, Mt. McKinley, 20,300 ft. (6187 m); lowest, Death Valley, 276 ft. (84 m) below sea level. 400,000,000 including… …
72rare-earth element — /rair errth /, Chem. any of a group of closely related metallic elements, comprising the lanthanides, scandium, and yttrium, that are chemically similar by virtue of having the same number of valence electrons. Also called rare earth metal. [1955 …
73oxygen group element — ▪ chemical element Introduction also called chalcogen, any of the five chemical elements making up Group 16 (VIa) of the periodic classification namely, oxygen, sulfur, selenium, tellurium, and polonium. (See Figure >.) A relationship among… …
74Mantle (geology) — For other uses, see Mantle (disambiguation). Earth cutaway from core to exosphere. The mantle is a part of a terrestrial planet or other rocky body large enough to have differentiation by density. The interior of the Earth, similar to the other… …
75carbon group element — ▪ chemical elements Introduction any of the five chemical elements that make up Group 14 (IVa) of the periodic table namely, carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead ( …
76Structure of the Earth — Earth cutaway from core to exosphere. Left picture is not to scale. The interior structure of the Earth, similar to the outer, is layered. These layers can be defined by either their chemical or their rheological properties. The Earth has an… …
77dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or …
78Lithosphere — The tectonic plates of the lithosphere on Earth …
79Empanada — Two empanadas (empanadillas) Origin Place of origin Spain Dish details …
80New Haven-style pizza — part of a series on Pizza …
