Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of …

Communities In Harmony Advocating For Learning and Kids or CHALK, founded in 1996 is a youth-led project providing a range of youth services with a specific focus on transformative …

2023年10月10日 · Chalk is a soft, white, porous, sedimentary rock composed primarily of the mineral calcite (calcium carbonate). It is often associated with marine environments and is …

Communities In Harmony Advocating For Learning and Kids or CHALK, founded in 1996 is a youth-led project providing a range of youth services with a specific focus on transformative …

Chalk is a variety of limestone composed mainly of calcium carbonate derived from the shells of tiny marine animals known as foraminifera and from the calcareous remains of marine algae …

The meaning of CHALK is a soft white, gray, or buff limestone composed chiefly of the shells of foraminifers. How to use chalk in a sentence.

CHALK definition: 1. a type of soft white rock 2. a stick of this rock or a similar substance used for writing or…. Learn more.

Communities in Harmony Advocating for Learning & Kids (CHALK), founded in 1996, is a youth-led, San Francisco program providing a range of youth services with a specific focus on …

2025年2月1日 · chalk, 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, …

A chalk is a soft, friable variety of limestone consisting of poorly lithified calcareous ooze, produced by the accumulation of planktonic organisms in a pelagic (open sea) environment. …