Calcium phosphate (V) occurs in nature gas

Calcium occurs in nature as:

How does calcium carbonate occurs in nature?

Calcium phosphate and calcium carbonate are secreted by_______cells

Calcium sulphate is found in nature in two forms, anhydrous calcium sulphate and hydrated calcium sulphate. When anhydrous calcium sulphate is heated with coke, sulphur dioxide gas is obtained. When hydrated calcium suphate is heated to 200^(@) C, it forms anhydrous salt. Q. The anhydrous calcium sulphate is called :

Calcium sulphate is found in nature in two forms, anhydrous calcium sulphate and hydrated calcium sulphate. When anhydrous calcium sulphate is heated with coke, sulphur dioxide gas is obtained. When hydrated calcium suphate is heated to 200^(@) C, it forms anhydrous salt. Q. The anhydrous calcium sulphate is called :

The nature of Calcium phosphate present in tooth enamel is: