
Further explanation
Diamonds are entirely composed of elemental carbon, structured into crystal forms due to immense pressure and temperature deep within the Earth's mantle. The chemical symbol for carbon is C.
Step-1: convert carats to grams
A carat is a weight unit used for diamonds and other gemstones. It is generally accepted that 1 carat equals 0.2 grams of carbon atoms.
Translating 1.3 carats into grams of carbon atoms:

Thus, a 1.3-carat diamond corresponds to 0.26 grams of carbon atoms.
Step-2: convert grams to moles
The atomic weight of carbon, as per the periodic table, is 12 g/mol. The equation linking moles, grams, and atomic weight is:

Transforming 0.26 grams into moles:

This results in 0.0217 moles of carbon atoms.
Final step: convert moles to atoms
The correlation between moles, atom count (N), and Avogadro's constant is represented as follows:


Adjusting to two decimal points gives
and expressed in scientific notation becomes 
This indicates that there are
atoms present in a 1.3-carat diamond.
Quick method

Rearranging it



Learn more
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- How many atoms of copper are present in one mole of copper?
- Which unit is used for measuring atomic mass?
Keywords: number of carbon atoms, in a 1.3-carat diamond, pure carbon, elemental, 100%, 1-carat equals 0.2 grams, moles, atomic mass, Avogadro's number, converting