Zinc, in commerce also spelter, is a chemical element; it has the symbol Zn and atomic number 30. It is the first element of group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is 2. Zinc is the 24th most abundant element in the Earth's crust and has five stable . The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest mineable amounts are found in Australia, A..
Mississippian copper plates, or plaques, are plain and repousséd plates of beaten copper crafted by peoples of the various regional expressions of the Mississippian culture between 800 to 1600 CE. They have been found as artifacts in in the American Midwest and Southeast. The plates, found as far afield as Florida, Georgia, Illinois, Mississippi, Oklahoma, Tennessee, and Wisconsin, were instrumental in the development of the archaeological concept known as the Southeastern Ceremonial Complex. Some of the..
A zygote (from Greek ζυγωτός zygōtos "joined" or "yoked", from ζυγοῦν zygoun "to join" or "to yoke"), is the initial cell formed when two gamete cells are joined by means of sexual reproduction. In multicellular organisms, it is the earliest developmental stage of the embryo. In single-celled organisms, the zygote divides to produce offspring, usually through Mitosis, the process of cell division.
