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Calcium Carbonate

Chalk, Limestone, Scale, Limescale, Kettle Fur, Plaque


Calcium Carbonate is chalk. The chemical formula is CaCO3 and its molecular weight is 100.

Calcium Carbonate is a combination of calcium, carbon, and oxygen in a relatively stable inert form. The White Cliffs of Dover are made of calcium carbonate, amazing as it may seem. What has happened is that tiny sea creatures over millions of years have left their tiny skeletons which have built up and compressed in a sedimentary fashion.

You can see what's happening in the natural course of events: Sea creatures are taking carbon dioxide out of the ecosystem and turning it into rock. Coral reefs do this, and once the CO2 has been turned to CaCO3, it tends to stay that way. This is carbon sequestration that actually works! (Unlike sweeping the CO2 under the carpet and hoping that no-one notices it escaping back into the atmosphere).

Some notable properties of calcium carbonate include...

* If it's made into small sticks it can be used for writing on a blackboard.

* It isn't the same as cheese at all.

* Hydrochloric acid makes it go FIZZ.

On the matter of the molecular weight of calcium carbonate being 100, it works like this:

CaCO3

Calcium ... 40

Carbon ... 12

Oxygen ... 16 x 3 = 48

40 + 12 + 48 = 100