Some of what I have read here leads me to believe that a TIA is a stroke that totally reverses itself and all symptoms go away within 24 hrs. Other postings indicate that if symptoms continue or periodically return, then that is an indication that it was more than just a TIA or that there are continuing problems.
Chalk /ËtÊÉËk/ is a soft, white, porous sedimentary carbonate rock, a form of limestone composed of the mineral calcite. Calcite is calcium carbonate or CaCO 3.It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells (coccoliths) shed from micro-organisms called coccolithophores.he most common forms are CaCO 3 (calcium carbonate) and CaO (calcium oxide). Small doses of chalk can also be used as an antacid. Additionally, the small particles of chalk make it a substance ideal for cleaning and polishing.
In the time before dry-erase boards, all education relied upon chalkboards made from slate, which is clay that has been cooked by heat and pressure deep within the earth. Chalk is a limestone made of the skeletons of millions of microbes that once lived at the bottom of the sea , so it's really a fossil. Bookmark/Search this post Home | Contact Us | Privacy Policy