Chalk It is formed in the sea by sub-microscopic plankton, which fall to the sea floor and are then consolidated and compressed during diagenesis into chalk rock. Most people first encounter the word "chalk" in school where it refers to blackboard chalk, which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to rough surfaces, allowing it to make writing that can be readily erased. Blackboard chalk manufacture now may utilize mineral chalk, other mineral sources of calcium carbonate, or the mineral gypsum (calcium sulfate). While gypsum-based blackboard chalk is the lowest cost to
Blackboard Inc. and notifications, academic or instructor notifications, or by school districts and communities to share time-sensitive information, such as in the case of natural disasters and campus emergencies. Blackboard Transact, formerly Blackboard Commerce Suite, is transaction processing system tied to university ID cards, which can be used for meal plans, vending machines and laundry services, and an e-commerce front end for the transaction system. The Transact system is NFC-compatible and its ID cards use contactless technology. Blackboard Transact also includes a program for off-campus vendors that allow students to pay for goods using their college's campus card. Blackboard Analytics was developed