Webchalk, soft, fine-grained, easily pulverized, white-to-grayish variety of limestone. Chalk is composed of the shells of such minute marine organisms as foraminifera, coccoliths, and … WebIndicate whether each of the following statements about the compound melatonin is true or false. a. Melatonin concentrations in the body decrease with age. b. Low levels of melatonin are associated with a “good night’s sleep.”. c. As a prescription drug, melatonin is used to treat “jet lag.”. d.

Is the chemical formula of chalk? - Studybuff

WebJan 5, 2024 · Is chalk organic chemistry? Chalk is organic in origin. It was formed over millions of years from the protective coverings of small organisms that lived in the seas … WebAug 29, 2024 · Chert is a chemical sedimentary rock that seems like it could be considered organic at times. It can contain remains of what is called siliceous ooze, or very small organic ocean life remains. Chert is very fine grained and … drawing of rx7

Is chalk an element or a compound? - Quora

WebMar 28, 2009 · Yes, chalk is a type of organic rock if it is natural. More specifically, it is a type of sedimentary rock made from a variety of limestone. Is chalk is organic or … WebChalk: composed of the carbonate tests (shells) of foraminifera (small organisms as small as a pin head). Travertine: limestone formed by the evaporation of water. Oolitic limestone: composed of oolites which form as tiny seed particles act as the nucleus for calcite precipitation; need a swashing effect. WebChalk: chalky texture Tufa: very porous, friable Travertine: bonded, coherent, denser than tufa Caliche: lime-rich deposit formed near surface: Calcareous Shale: limy shale, etc. … drawing of rocketship