**Symbol**: mol / **Base data**: material amount.

SI base unit. Elementary entity that has the same number as atoms existing in 0.012 kg of carbon-12, or the material amount of a system composed of that mass.

**1 mol of carbon atoms is equal to 12g of atoms in carbon-12**

When converting the weight of 1 carbon atom to the whole number of 12, the number of oxygen atoms would be 16. So, if you collected a certain number of carbon atoms, it would come to 12 g. How many grams would it come to if you collected the same number of oxygen atoms? That’s right, you guessed it – 16 grams. This amount is “1 mole”.

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