the isotopic composition of all elements
81Tektite — Tektites (from Greek tektos , molten) are natural glass objects up to a few centimeters in size, which most scientists argue were formed by the impact of large meteorites on Earth s surface. Tektites are typically black or olive green, and their… …
82plate tectonics — plate tectonic, adj. Geol. a theory of global tectonics in which the lithosphere is divided into a number of crustal plates, each of which moves on the plastic asthenosphere more or less independently to collide with, slide under, or move past… …
83rock — rock1 rockless, adj. rocklike, adj. /rok/, n. 1. a large mass of stone forming a hill, cliff, promontory, or the like. 2. Geol. a. mineral matter of variable composition, consolidated or unconsolidated, assembled in masses or considerable… …
84Rock — /rok/, n. a male given name. * * * I In geology, a naturally occurring and coherent aggregate of minerals. The three major classes of rock igneous, sedimentary, and metamorphic are based on the processes that formed them. These three classes are… …
85Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …
86astronomy — /euh stron euh mee/, n. the science that deals with the material universe beyond the earth s atmosphere. [1175 1225; ME astronomie ( < AF) < L astronomia < Gk. See ASTRO , NOMY] * * * I Science dealing with the origin, evolution, composition,… …
87moon — mooner, n. moonless, adj. /moohn/, n. 1. the earth s natural satellite, orbiting the earth at a mean distance of 238,857 miles (384,393 km) and having a diameter of 2160 miles (3476 km). 2. this body during a particular lunar month, or during a… …
88Moon — /moohn/, n. Sun Myung /sun myung/, born 1920, Korean religious leader: founder of the Unification Church. * * * Sole natural satellite of Earth, which it orbits from west to east at a mean distance of about 238,900 mi (384,400 km). It is less… …
89Abiogenic petroleum origin — is a largely abandoned hypothesis that was proposed as an alternative to theory of biological petroleum origin. It was relatively popular in the past, but it went largely forgotten at the end of the 20th century after it failed to predict the… …
90Kilogram — Kg redirects here. For other uses, see Kg (disambiguation). Kilogram A computer generated image of the international prototype kilogram (IPK). The IPK is the kilogram. The IPK, which is roughly the size of a golf ball, sits here alongside a ruler …
